Breast carcinoma (BC) have been extensively profiled by high-throughput technologies for over a decade, and broadly speaking, these studies can be grouped into those that seek to identify patient subtypes (studies of heterogeneity) or those that seek to identify gene signatures with prognostic or predictive capacity. The shear number of reported signatures has led to speculation that everything is prognostic in BC. Here we show that this ubiquity is an apparition caused by a poor understanding of the inter- relatedness between subtype and the molecular determinants of prognosis. Our approach constructively shows how to avoid confounding due to a patient's subtype, clinicopathological or treatment profile. The approach identifies patients who are predicted to have good outcome at time of diagnosis by all available clinical and molecular markers, but who experience a distant metastasis within five years. These inherently difficult patients (~7% of BC) are prioritized for investigations of intra-tumoral heterogeneity.
The prognostic ease and difficulty of invasive breast carcinoma.
Age, Disease stage, Time
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HDAC4 reduction: a novel therapeutic strategy to target cytoplasmic huntingtin and ameliorate neurodegeneration.
Sex, Age, Specimen part
View SamplesThis study is a follow-up to GSE35790.
Transcriptional regulatory logic of the diurnal cycle in the mouse liver.
Sex, Specimen part, Time
View SamplesHistone deacetylase (HDAC) 4 is a transcriptional repressor that contains a glutamine rich domain. We hypothesised that it may be involved in the molecular pathogenesis of Huntingtons disease (HD), a protein folding neurodegenerative disorder caused by an aggregation-prone polyglutamine expansion and transcriptional dysregulation. We found that HDAC4 interacts with huntingtin in a polyglutamine-length dependent manner and co-localises with cytoplasmic inclusions. We show that HDAC4 reduction delayed cytoplasmic aggregate formation, restored Bdnf transcript levels and rescued neuronal and cortico-striatal synaptic function in HD mouse models. This was accompanied by an improvement in motor co-ordination, neurological phenotypes and increased lifespan. Surprisingly, HDAC4 reduction had no effect on global transcriptional dysfunction and did not modulate nuclear huntingtin aggregation. Our results define a crucial role for cytoplasmic aggregation in the molecular pathology of HD. HDAC4 reduction presents a novel strategy for targeting huntingtin aggregation which may be amenable to small molecule therapeutics.
HDAC4 reduction: a novel therapeutic strategy to target cytoplasmic huntingtin and ameliorate neurodegeneration.
Sex, Age, Specimen part
View SamplesHistone deacetylase (HDAC) 4 is a transcriptional repressor that contains a glutamine rich domain. We hypothesised that it may be involved in the molecular pathogenesis of Huntingtons disease (HD), a protein folding neurodegenerative disorder caused by an aggregation-prone polyglutamine expansion and transcriptional dysregulation. We found that HDAC4 interacts with huntingtin in a polyglutamine-length dependent manner and co-localises with cytoplasmic inclusions. We show that HDAC4 reduction delayed cytoplasmic aggregate formation, restored Bdnf transcript levels and rescued neuronal and cortico-striatal synaptic function in HD mouse models. This was accompanied by an improvement in motor co-ordination, neurological phenotypes and increased lifespan. Surprisingly, HDAC4 reduction had no effect on global transcriptional dysfunction and did not modulate nuclear huntingtin aggregation. Our results define a crucial role for cytoplasmic aggregation in the molecular pathology of HD. HDAC4 reduction presents a novel strategy for targeting huntingtin aggregation which may be amenable to small molecule therapeutics.
HDAC4 reduction: a novel therapeutic strategy to target cytoplasmic huntingtin and ameliorate neurodegeneration.
Sex, Age, Specimen part
View SamplesHuntingtons disease (HD) is a neurodegenerative disorder that is associated with the deposition of proteinaceous aggregates in the brains of HD patients and mouse models. Previous studies have suggested that wide-scale disruption of protein homeostasis occurs in protein folding diseases. Protein homeostasis can be maintained by activation of the heat shock response (HSR) via the transcription factor heat shock factor 1 (HSF1), the pharmacological activation of which can be achieved by Hsp90 inhibition and has been demonstrated to be beneficial in cell and invertebrate models of HD. Whether the HSR is functional in HD and whether its activation has therapeutic potential in mammalian HD models is currently unknown. To address these issues, we used a novel, brain penetrant Hsp90 inhibitor to activate the HSR in brain after systemic administration. Microarrays, quantitative PCR and western blotting showed that the HSR becomes impaired with disease progression in two mouse models of HD and that this originates at the level of transcription.
Altered chromatin architecture underlies progressive impairment of the heat shock response in mouse models of Huntington disease.
Sex, Age, Specimen part, Treatment
View SamplesVirus infection and over expression of protein in cytosol induce a subset of HSP70s. We named this response the Cytosolic Protein Response (CPR) and have been investigating it in the context of a parallel mechanism in the soluble cytosol with the UPR, and as a subcomponent of the larger HS response. This experiment was carried out to study the transcriptional aspect of CPR. In this analysis, we have triggered CPR by infiltrating proline analogue, L-azetidine-2-carboxylic acid (AZC) into Arabidopsis mature leaves. Since AZC trigger unfolded protein response(UPR) in ER as well as CPR, we have included tunicamycin treatment, which is a specific inducer of UPR to subtract the effect of UPR from the AZC response. Heat shocked samples were included to identify CPR as a subcomponent of larger HS response.
The cytosolic protein response as a subcomponent of the wider heat shock response in Arabidopsis.
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View SamplesReversible protein acetylation provides a central mechanism for controlling gene expression and cellular signaling events. It is governed by the antagonistic commitment of two enzymes families: the histone acetyltransferases (HATs) and the histone deacetylases (HDACs). HDAC4, like its class IIa counterparts, is a potent transcriptional repressor through interactions with tissue-specific transcription factors via its N-terminal domain. Whilst the lysine deacetylase activity of the class IIa HDACs is much less potent than that of the class I enzymes, HDAC4 has been reported to influence protein deacetylation through its interaction with HDAC3.
HDAC4 does not act as a protein deacetylase in the postnatal murine brain in vivo.
Sex, Specimen part
View SamplesUpstream Binding Factor (UBF) is a unique multi-HMGB-box protein first identified as a co-factor in RNA polymerase I (RPI/PolI) transcription. However, its poor DNA sequence selectivity and its ability to generate nucleosome-like nucleoprotein complexes suggest a more generalized role in chromatin structure. We previously showed that extensive depletion of UBF reduced the number of actively transcribed ribosomal RNA (rRNA) genes, but had little effect on rRNA synthesis rates or cell proliferation, leaving open the question of its requirement for RPI transcription. Using conditional gene deletion in mouse, we now show that UBF is indeed essential for transcription of the rRNA genes.
Conditional inactivation of Upstream Binding Factor reveals its epigenetic functions and the existence of a somatic nucleolar precursor body.
Specimen part, Time
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No associated publication
Sex, Specimen part
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