Tumor cells exhibit aberrant metabolism characterized by high glycolysis even in the presence of oxygen. This metabolic reprogramming, known as the Warburg effect, provides tumor cells with the substrates and redox potential required for the generation of biomass. Here, we show that the mitochondrial NAD-dependent deacetylase SIRT3 is a crucial regulator of the Warburg effect. SIRT3 loss promotes a metabolic profile consistent with high glycolysis required for anabolic processes in vivo and in vitro. Mechanistically, SIRT3 mediates metabolic reprogramming independently of mitochondrial oxidative metabolism and through HIF1a, a transcription factor that controls expression of key glycolytic enzymes. SIRT3 loss increases reactive oxygen species production, resulting in enhanced HIF1a stabilization. Strikingly, SIRT3 is deleted in 40% of human breast cancers, and its loss correlates with the upregulation of HIF1a target genes. Finally, we find that SIRT3 overexpression directly represses the Warburg effect in breast cancer cells. In sum, we identify SIRT3 as a regulator of HIF1a and a suppressor of the Warburg effect.
SIRT3 opposes reprogramming of cancer cell metabolism through HIF1α destabilization.
Specimen part
View SamplesZebrafish of two different age groups (12 and 36 months) were treated with low amounts of rotenone (mild stress) and compared to untreated zebrafish. Two different durations were used (3 and 8 weeks). Illumina sequencing (HiSeq2000) was applied to generate 50bp single-end reads. Jena Centre for Systems Biology of Ageing - JenAge (www.jenage.de) Overall design: 68 sample: 3 tissues (brain, liver, skin); 2 age groups (12 and 36 months); controls and rotenone treated samples; 2-6 biological replicates for each group
Longitudinal RNA-Seq Analysis of Vertebrate Aging Identifies Mitochondrial Complex I as a Small-Molecule-Sensitive Modifier of Lifespan.
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View SamplesThis SuperSeries is composed of the SubSeries listed below.
Knockout of G protein β5 impairs brain development and causes multiple neurologic abnormalities in mice.
Specimen part
View SamplesThe restoration of catalytic activity to mutant enzymes by small molecules is well-established for in vitro systems. Here we show that the protein tyrosine kinase Src R388A mutant can be rescued in live cells using the small molecule imidazole. Cellular rescue of a v-Src homolog was rapid and reversible and conferred predicted oncogenic properties. Using chemical rescue in combination with mass spectrometry, six known Src kinase substrates were confirmed, and several new protein targets identified. Chemical rescue data suggests that c-Src is active under basal conditions. Rescue of R388A c-Src also allowed contributions of Src to the MAP kinase pathway to be clarified. This chemical rescue approach is likely to be of broad utility in cell signaling.
Chemical rescue of a mutant enzyme in living cells.
No sample metadata fields
View SamplesConjugated linoleic acid (CLA), a class of fatty acids found in beef and dairy products, has been shown to inhibit tumorigenesis in a variety of cancer model systems. Based on previously well-documented anti-tumor activity of CLA in rodent models of breast cancer, a pilot study was initiated to examine the effect of dietary CLA in a well-established transgenic model of breast cancer. Western blots were performed for the detection of AKT, c-Src, ERK1/2, and Cdc24. CLA significantly increased tumor burden (p<0.1) independent of an increase in oncogenic signaling. Mammary gland whole mounts indicated a loss of mammary adipose and extensive epithelial expansion in CLA-treated animals. Microarray analysis indicated a significant reduction in cytoskeletal related genes with at least a two-fold decrease in five out of six CLA-fed animals compared to untreated controls. Reduction of Cdc42, a key regulator of cell adhesion and cytoskeletal arrangements, was confirmed at the protein level by western blot (p<0.01). These findings suggest that dietary CLA may advance the malignant phenotype by promoting a loss of cell polarity and adhesion in the mammary gland epithelium. This action may have serious clinical implications for a subset high-risk population and warrants further investigation.
Pilot study on the effects of dietary conjugated linoleic acid on tumorigenesis and gene expression in PyMT transgenic mice.
Sex, Age, Specimen part
View SamplesNlrc5 is encoding a Nod-like receptor protein NLRC5/NOD27. To check the involvement of Nlrc5 in antiviral response, we examined gene expression profile in wild-type and Nlrc5 knockout GM-CSF bone marrow macrophage with using microarrays.
NLRC5 deficiency does not influence cytokine induction by virus and bacteria infections.
Specimen part, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Time of feeding and the intrinsic circadian clock drive rhythms in hepatic gene expression.
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View SamplesRestricted feeding impacts the hepatic circadian clock of WT mice. Cry1, Cry2 double KO mice lack a circadian clock and are thus expected to show rhythmical gene expression in the liver. Imposing a temporally restricted feeding schedule on these mice shows how the hepatic circadian clock and rhythmic food intake regulate rhythmic transcription in parallel
Time of feeding and the intrinsic circadian clock drive rhythms in hepatic gene expression.
No sample metadata fields
View SamplesTemporally restricted feeding is known to impact the circadian clock. This dataset shows the effects of temporally restricted feeding on the hepatic transcriptome.
Time of feeding and the intrinsic circadian clock drive rhythms in hepatic gene expression.
No sample metadata fields
View SamplesTemporally restricted feeding has a profound effect on the circadian clock. Fasting and feeding paradigms are known to influence hepatic transcription. This dataset shows the dynamic effects of refeeding mice after a 24hour fasting period.
Time of feeding and the intrinsic circadian clock drive rhythms in hepatic gene expression.
No sample metadata fields
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