Luminal breast cancers express estrogen (ER) and progesterone (PR) receptors, and respond to endocrine therapies. However, some ER+PR+ tumors display intrinsic or acquired resistance, possibly related to PR. Two PR isoforms, PR-A and PR-B, regulate distinct gene subsets that may differentially influence tumor fate. A high PR-A:PR-B ratio is associated with poor prognosis and tamoxifen resistance. We speculate that excessive PR-A marks tumors that will relapse early. Here we address mechanisms by which PR-A regulate transcription, focusing on SUMOylation. We use receptor mutants and synthetic promoter/reporters to show that SUMOylation deficiency or the deSUMOylase SENP1 enhance transcription by PR-A, independent of the receptors dimerization interface or DNA binding domain. De-SUMOylation exposes the agonist properties of the antiprogestin RU486. Thus, on synthetic promoters, SUMOylation functions as an independent brake on transcription by PR-A. What about PR-A SUMOylation of endogenous human breast cancer genes? To study these, we used gene expression profiling. Surprisingly, PR-A SUMOylation influences progestin target genes differentially, with some upregulated, others downregulated, and others unaffected. Hormone-independent gene regulation is also PR-A SUMOylation dependent. Several SUMOylated genes were analyzed in clinical breast cancer database. In sum, we show that SUMOylation does not simply repress PR-A. Rather, it regulates PR-A activity in a target selective manner including genes associated with poor prognosis, shortened survival, and metastasis.
SUMOylation Regulates Transcription by the Progesterone Receptor A Isoform in a Target Gene Selective Manner.
Specimen part, Treatment
View SamplesGamma oscillations (20-50Hz) are a common local field potential signature in many brain regions that are generated by a resonant circuit between fast-spiking parvalbumin (PV)-positive interneurons and pyramidal cells. Changes in the magnitude and frequency of gamma have been observed in several neuropsychiatric disorders. However, it is unclear how disruptions in gamma oscillations affect cellular pathologies seen in these disorders. Here, we investigate this using the 5XFAD mouse model of Alzheimer’s disease (AD) and find reduced power and magnitude of behaviorally driven gamma oscillatory activity — even before the onset of plaque formation or measurable cognitive decline. Because of the early onset, we aimed to determine if exogenous manipulations of gamma could influence the progression of disease pathology. We find that driving PV-positive neurons at gamma frequency (40Hz) using channelrhodopsin-2 reduced total levels of amyloid-ß (Aß) 40 and 42 isoforms in the hippocampus of 5XFAD mouse. Driving PV-positive neurons at other frequencies, or driving excitatory neurons, did not reduce Aß levels. Furthermore, driving PV-positive neurons reduced enlarged endosomes in hippocampal neurons and cleavage intermediates of APP in 5XFAD mouse. Gene expression profiling revealed a neuroprotective response with morphological transformation of microglia and markedly increased phagocytosis of Aß by microglia. Inspired by these observations, we designed a non-invasive light-flickering paradigm that drives 40Hz gamma activity in mouse visual cortex. The light-flickering paradigm profoundly reduced Aß40 and Aß42 levels in the visual cortex of pre-symptomatic mice and greatly mitigated plaque load in the visual cortex of aged, symptomatic mice. This reduction was completely blocked by a GABA-A antagonist, providing further support for an essential role of GABAergic signaling in mediating neuroprotective gamma activity. Overall, our findings uncover a dramatic and previously unappreciated function of the brain’s endogenous gamma rhythms in reducing the production and increasing the clearance of Aß peptides, whose accumulation is believed to drive the pathogenesis of AD. Overall design: Two to four weeks following virus injection and implant placement, hippocampal CA1 neurons were optigenetically manipulated. During the experiment, 1mW of optical stimulation was delivered for 1h using a 40Hz stimulation protocol.
Gamma frequency entrainment attenuates amyloid load and modifies microglia.
Age, Specimen part, Cell line, Subject
View SamplesMicroarray is widely used to monitor gene expression changes in breast cancer. The transcriptomic changes in breast cancer is commonly occured during the transition of normal cells to cancerous cells. This is the first study on gene expression profiling of multi ethnic of Malaysian breast cancer patients (Malays, Chinese and Indian). We aim to identify differentially expressed genes between tumors and normal tissues. We have identified a set of 33 significant differentially expressed genes in the tumor vs. normal group at p<0.001.
Gene expression patterns distinguish breast carcinomas from normal breast tissues: the Malaysian context.
Specimen part, Disease stage, Race
View SamplesBackground: To date, few studies have systematically characterized microarray gene expression signal performance with degraded RNA from formalin-fixed paraffin-embedded (FFPE) specimens in comparison to intact RNA from unfixed fresh-frozen (FF) specimens.
Quantitative expression profiling in formalin-fixed paraffin-embedded samples by affymetrix microarrays.
Specimen part, Subject
View SamplesPsychological, psychosocial and physical stress are major risk factors, which enhance the development of sporadic late-onset Alzheimer`s disease. The chronic unpredictable mild stress model mimics those risk factors and triggers signs of neurodegeneration and neuropathological features of sporadic AD such as tau hyperphosphorylation and enhanced amyloid beta generation. The study investigated the impact of chronic unpredictable mild stress on signs of neurodegeneration by analyzing hippocampal gene expression with whole genome microarray gene expression profiling.
Inhibition of ACE Retards Tau Hyperphosphorylation and Signs of Neuronal Degeneration in Aged Rats Subjected to Chronic Mild Stress.
Sex, Age, Specimen part
View SamplesOver-expression of the polycomb group gene BMI-1 is implicated in the pathogenesis of many human cancers. In this study, we investigate the role of BMI-1 as a functional oncogene in the Ewings Sarcoma Family of Tumors (ESFT), a highly aggressive group of bone and soft tissue tumors. Our data show that BMI-1 is highly expressed by the majority of primary ESFT and ESFT cell lines. However, in contrast to previous reports in other human cancer cell types, knockdown of BMI-1 in ESFT cell lines has no effect on cell survival. Instead, gain and loss of function studies in vitro and in vivo demonstrate that BMI-1 promotes the anchorage independent growth and tumorigenicity of ESFT. Importantly, we also find that modulation of BMI-1 alters the tumorigenicity of both p16-wild type and p16-null cell lines and that BMI-1-mediated effects on growth promotion are independent of CDKN2a repression. Gene expression profiling of ESFT cells following BMI-1 modulation reveals novel downstream effectors of BMI-1 function including key developmental, cell:cell and cell:matrix adhesion pathways. These data support a central role for BMI-1 in the pathogenesis of ESFT and reveal that p16-independent functions of BMI-1 are largely responsible for its oncogenic function in this tumor family.
BMI-1 promotes ewing sarcoma tumorigenicity independent of CDKN2A repression.
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View SamplesPowdery mildew, caused by the fungus Blumeria graminis (DC) Speer, is one of the most important foliar diseases of cereals worldwide. It is an obligate biotrophic parasite, colonising leaf epidermal cells to obtain nutrients from the plant cells without killing them. Syringolin A (sylA), a circular peptide secreted by the phytopathogenic bacterium Pseudomonas syringae pv. syringae, triggers a hypersensitive cell death reaction (HR) at infection sites when sprayed onto powdery mildew infected wheat which essentially eradicates the fungus. The rational was to identify genes whose expression was specifically regulated during HR, i.e. genes that might be involved in the switch of compatibility to incompatibility.<br></br>Powdery mildew-infected or uninfected plants were treated with syringolin two days after infection and plant material for RNA extraction was collected at 0.5, 1, 2, 4, 8, 12 hours after treatment (hat), resulting in an early (2 and 4 hat) and late pool (8 and 12 hat). Plant material that was uninfected prior to syringolin treatment was collected 8 and 12 hat (late pool of uninfected plant material), and 1 hat, respectively.
Transcriptional changes in powdery mildew infected wheat and Arabidopsis leaves undergoing syringolin-triggered hypersensitive cell death at infection sites.
Compound, Time
View SamplesWe tested the effects of the antioxidant NAC (N-Acetyl-Cysteine) on gene expression in Nkx3.1-deficient mouse prostate.
Antioxidant treatment promotes prostate epithelial proliferation in Nkx3.1 mutant mice.
Age, Specimen part
View SamplesDifferent fusion oncogenes in acute myeloid leukemia (AML) have distinct clinical and laboratory features suggesting different modes of malignant transformation. Here we compare the in vitro effects of representatives of major groups of AML fusion oncogenes on primary human CD34+ cells.
In vitro transformation of primary human CD34+ cells by AML fusion oncogenes: early gene expression profiling reveals possible drug target in AML.
Specimen part
View SamplesThe initial segment of the epididymis is vital for male fertility, therefore, it is important to understand the mechanisms that regulate this important region. Deprival of testicular luminal fluid factors/lumicrine factors from epididymis, a subset of cells within the initial segment undergo apoptosis. In this study, microarray analyses was used to examine early changes in the downstream signal transduction pathways following the loss of lumicrine factors, and we discovered the following cascade of events leading to loss of protection and eventual apoptosis. First, mRNA expression of several key components of ERK pathway decreased sharply after 6 hours of loss protection from testicular lumicrine factors. After 12 hours, the levels of mRNA expression of STAT and NF-B pathways components increased, mRNA expression of genes encoding cell cycle inhibitors increased. After 18 hours of loss protection from testicular lumicrine factors, apoptosis was observed in the initial segment. In conclusion, testicular lumicrine factors protect the cells of the initial segment by activating ERK pathway, repressing STAT and NF-B pathways, and preventing a cascade of reactions leading to apoptosis.
Testicular lumicrine factors regulate ERK, STAT, and NFKB pathways in the initial segment of the rat epididymis to prevent apoptosis.
Sex, Specimen part, Time
View Samples