This SuperSeries is composed of the SubSeries listed below.
Expression of microRNA and their gene targets are dysregulated in preinvasive breast cancer.
Sex, Age, Specimen part, Disease
View SamplesIntroduction: microRNAs (miRNAs) are short non-coding RNAs that negatively regulate gene expression and may play a causal role in invasive breast cancer. Since many genetic aberrations of invasive disease are detectable in earlier stages, we hypothesized that miRNA expression dysregulation and the predicted changes in gene expression would also be found in early breast neoplasias. Methods: Expression profiling of 365 miRNAs by RT-qPCR was combined with laser-capture microdissection to obtain an epithelial specific miRNA expression signature of normal breast epithelium (n=9) and of paired samples of histologically normal epithelium (HN) and ductal carcinoma in situ (DCIS) (n=16). To determine how miRNAs may control the expression of co-dysregulated mRNAs we also performed gene expression microarray analysis in the same paired HN and DCIS samples and integrated this with miRNA-target prediction. We further validated several target pairs by modulating the expression levels of miRNAs in MCF7 cells and measured the expression of target mRNAs and proteins. Results: Thirty-five miRNAs were aberrantly expressed between RM, HN and DCIS. Twenty-nine miRNAs and 420 mRNAs were aberrantly expressed between HN and DCIS. Combining these two datasets with miRNA-target prediction we identified two established target pairs (miR-195:CCND1 and miR-21:NFIB) and tested several novel miRNA:mRNA target pairs. Over-expression of the putative tumor-suppressor miR-125b, under-expressed in DCIS, repressed the expression of MEMO1, which is required for ErbB2-driven cell motility (also a target of miR-125b); and NRIP1/RIP140, which modulates the transcriptional activity of the estrogen receptor. Knockdown of the putative oncogenic miRNAs miR-182 and miR-183, both highly over-expressed in DCIS, increased the expression of CBX7 (which regulates E-cadherin expression), DOK4, NMT2, and EGR1. Augmentation of CBX7 by knockdown of miR-182 expression, in turn, positively regulated the expression of E-cadherin, a key protein involved in maintaining normal epithelial cell morphology which is commonly lost during neoplastic progression. Conclusions: These data provide the first miRNA expression profile of normal breast epithelium and of pre-invasive breast carcinoma. Further, we demonstrate that altered miRNA expression can modulate gene expression changes that characterize these early cancers. We conclude that miRNA dysregulation likely plays a substantial role in early breast cancer development.
Expression of microRNA and their gene targets are dysregulated in preinvasive breast cancer.
Sex, Age, Specimen part, Disease
View SamplesWe report the effect of DKK1 treatment during culture on the length and transcriptome of embryos on day 15 of development, supporting the notion that changes early in development affect later stages of development. Overall design: Bovine embryos were produced in vitro and exposed to either 0 or 100 ng/ml DKK1 from day 5 to 7 of culture. Embryos were transferred on day 7 and recovered on day 15 for evaluation of length and transciptome
Dickkopf-related protein 1 is a progestomedin acting on the bovine embryo during the morula-to-blastocyst transition to program trophoblast elongation.
Treatment, Subject
View SamplesRecent reports have proposed a new paradigm for obtaining mature somatic cell types from fibroblasts without going through a pluripotent state, by briefly expressing canonical iPSC reprogramming factors Oct4, Sox2, Klf4 and c-Myc (abbreviated as OSKM), in cells expanded in lineage differentiation promoting conditions. Here we apply genetic lineage tracing for endogenous Nanog, Oct4 and X chromosome reactivation during OSKM induced trans-differentiation, as these molecular events mark final stages for acquisition of induced pluripotency. Remarkably, the vast majority of reprogrammed cardiomyocytes or neural stem cells derived from mouse fibroblasts via OSKM mediated trans-differentiation were attained after transient acquisition of pluripotency, and followed by rapid differentiation. Our findings underscore a molecular and functional coupling between inducing pluripotency and obtaining “trans-differentiated” somatic cells via OSKM induction, and have implications on defining molecular trajectories assumed during different cell reprogramming methods. Overall design: poly RNA-Seq was measured before, during and after conversion of mouse embryonic fibroblasts to neural stem cells using OSKM trans-differentiation method.
Transient acquisition of pluripotency during somatic cell transdifferentiation with iPSC reprogramming factors.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
siPools: highly complex but accurately defined siRNA pools eliminate off-target effects.
Cell line
View SamplesShort interfering RNAs (siRNA) are widely used as tool for gene inactivation in basic research and therapeutic applications. One of the major shortcomings of siRNA experiments are sequence-specific Off-target effects. Such effects are largely unpredictable because siRNAs can affect partially complementary sequences and function like microRNAs (miRNAs), which inhibit gene expression on mRNA stability or translational levels.
siPools: highly complex but accurately defined siRNA pools eliminate off-target effects.
Cell line
View SamplesBackground & Aims: Ursodeoxycholic acid (UDCA) attenuates chemical and colitis-induced colon carcinogenesis in animal models. We investigated its mechanism of action on normal intestinal cells, in which carcinogenesis- or inflammation-related alterations do not interfere with the result. Methods: Alterations of gene expression were identified in Affymetrix arrays in isolated colon epithelium of mice fed with a diet containing 0.4% UDCA and were confirmed in the normal rat intestinal cell line IEC-6 by RT-PCR. The effect of the insulin receptor substrate 1 (Irs-1) expression and of ERK phosphorylation on proliferation was investigated in vitro by flow cytometry, western blotting, siRNA-mediated gene suppression or by pharmacological inhibition of the kinase activity. The ERK1-effect on Irs-1 transcription was tested in a reporter system. Results: UDCA-treatment in vivo suppressed potential pro-proliferatory genes including Irs-1 and reduced cell proliferation by more than 30%. In vitro it neutralised the proliferatory signals of IGF-1 and EGF and slowed down the cell cycle. Irs-1 transcription was suppressed due to high ERK1 activation. Both Irs-1 suppression and the persistent high ERK activation inhibited proliferation. Conversely, the decrease of phosphorylation of ERK1 (but not ERK2) or of its expression partially abrogated the inhibitory effects of UDCA. Conclusions: UDCA inhibits proliferation of intestinal epithelial cells by acting upon IGF-1 and EGF pathways and targeting ERK1 and, consequently, Irs-1. The inhibition of these pathways adds a new dimension to the physiological and therapeutic action of UDCA and, since both pathways are activated in inflammation and cancer, suggests new applications of UDCA in chemoprevention and chemotherapy.
UDCA slows down intestinal cell proliferation by inducing high and sustained ERK phosphorylation.
Specimen part, Cell line
View SamplesWe used microarrays to assess gene expression in proliferating ovarian cancer cell lines
Synergistic inhibition of ovarian cancer cell growth by combining selective PI3K/mTOR and RAS/ERK pathway inhibitors.
Specimen part, Cell line
View SamplesGene expression profiles were examined in whole lung tissue collected from male and female Long-Evans rats at different time points after inoculation with Seoul virus (i.e., the species-specific hantavirus that infects Norway rats)
Sex differences in the recognition of and innate antiviral responses to Seoul virus in Norway rats.
No sample metadata fields
View SamplesAdaptation of C. elegans to hypertonic environments involves the accumulation of the organic osmolyte glycerol via transcriptional upregulation of the glycerol biosynthestic enzyme gpdh-1. A number of mutants, termed osmotic stress resistant (osr) mutants, have been identified. osr mutants cause constitutive upregulation of gpdh-1 and confer extreme resistance to hypertonicity. We tested the hypothesis that osr mutants broadly activate a gene expression program normally activated by osmotic stress in wild type animals using Affymterix microarray analysis of the hypertonic stress response in wild type animals and of constituitive gene expression changes in five osr mutants.
Genetic and physiological activation of osmosensitive gene expression mimics transcriptional signatures of pathogen infection in C. elegans.
Specimen part
View Samples