The mechanisms involved in epithelium-stroma interactions remain poorly understood, despite the importance of the microenvironment during tumorigenesis. Here, we studied the role of Ets2 transcrpiton factor in tumor associated fibroblasts in the MMTV-ErbB2 mammary tumor model. Inactivation of Ets2 specifically in fibroblasts using Fsp-cre significantly reduced tumor growth, in contrast to Ets2 inactivation in epithelium in which no differences in tumor growth were observed.
Ets2 in tumor fibroblasts promotes angiogenesis in breast cancer.
Age, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Redeployment of Myc and E2f1-3 drives Rb-deficient cell cycles.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
E2f8 mediates tumor suppression in postnatal liver development.
Age, Specimen part
View SamplesPTEN imparts tumor suppression in mice by cell autonomous and non-autonomous mechanisms. Whether these two tumor suppressor roles are mediated through similar or distinct signaling pathways is not known. Here we generated and analyzed knockin mice that express a series of human cancer-derived mutant alleles of PTEN in either stromal or tumor cell compartments of mammary glands. We find that cell non-autonomous tumor suppression by Pten in stromal fibroblasts strictly requires activation of P-Akt signaling, whereas cell autonomous tumor suppression in epithelial tumor cells is independent of overt canonical pathway activation
Noncatalytic PTEN missense mutation predisposes to organ-selective cancer development in vivo.
Age, Specimen part
View SamplesNuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that induces a battery of cytoprotective genes in response to oxidative/electrophilic stress. Kelch-like ECH associating protein 1 (Keap1) sequesters Nrf2 in the cytosol. The purpose of this study was to investigate the role of Nrf2 in regulating the mRNA of genes encoding drug metabolizing enzymes and xenobiotic transporters. Microarray analysis was performed in livers of Nrf2-null, wild-type, Keap1-knockdown mice with increased Nrf2 activation, and Keap1-hepatocyte knockout mice with maximum Nrf2 activation. In general, Nrf2 did not have a marked effect on uptake transporters, but the mRNAs of organic anion transporting polypeptide 1a1, sodium taurocholate cotransporting polypeptide, and organic anion transporter 2 were decreased with Nrf2 activation. The effect of Nrf2 on cytochrome P450 (Cyp) genes was minimal, with only Cyp2a5, Cyp2c50, Cyp2c54, and Cyp2g1 increased, and Cyp2u1 decreased with enhanced Nrf2 activation. However, Nrf2 increased mRNA of many other phase-I enzymes, such as aldo-keto reductases, carbonyl reductases, and aldehyde dehydrogenase 1. Many genes involved in phase-II drug metabolism were induced by Nrf2, including glutathione S -transferases, UDP- glucuronosyltransferases, and UDP-glucuronic acid synthesis enzymes. Efflux transporters, such as multidrug resistance-associated proteins, breast cancer resistant protein, as well as ATP-binding cassette g5 and g8 were induced by Nrf2. In conclusion, Nrf2 markedly alters hepatic mRNA of a large number of drug metabolizing enzymes and xenobiotic transporters, and thus Nrf2 plays a central role in xenobiotic metabolism and detoxification.
Effect of graded Nrf2 activation on phase-I and -II drug metabolizing enzymes and transporters in mouse liver.
Sex, Age, Specimen part
View SamplesAtherosclerosis and pressure overload are major risk factors for the development of heart failure in patients. Cardiac hypertrophy often precedes the development of heart failure. However, underlying mechanisms are incompletely understood. To investigate pathomechanisms underlying the transition from cardiac hypertrophy to heart failure we used experimental models of atherosclerosis- and pressure overload-induced cardiac hypertrophy and failure, i.e. apolipoprotein E (apoE)-deficient mice, which develop heart failure at an age of 18 months, and non-transgenic C57BL/6J (B6) mice with heart failure triggered by 6 months of pressure overload induced by abdominal aortic constriction (AAC). The development of heart failure was monitored by echocardiography, invasive hemodynamics and histology. The microarray gene expression study of cardiac genes was performed with heart tissue from failing hearts relative to hypertrophic and healthy heart tissue, respectively. The microarray study revealed that the onset of heart failure was accompanied by a strong up-regulation of cardiac lipid metabolism genes involved in fat synthesis, storage and oxidation.
Up-regulation of the cardiac lipid metabolism at the onset of heart failure.
Age, Specimen part, Disease
View SamplesHeart failure is a leading cause of cardiovascular mortality with limited options for treatment. We used 18 month-old apolipoprotein E (apoE)- deficient mice as a model of atherosclerosis-induced heart failure to analyze whether the anti-ischemic drug ranolazine could retard the progression of heart failure. The study showed that 2 months of ranolazine treatment improved cardiac function of 18 month-old apoE-deficient mice with symptoms of heart failure as assessed by echocardiography. To identify changes in cardiac gene expression induced by treatment with ranolazine a microarray study was performed with heart tissue from failing hearts relative to ranolazine-treated and healthy control hearts. The microarray approach identified heart failure-specific genes that were normalized during treatment with the anti-ischemic drug ranolazine.
Up-regulation of the cardiac lipid metabolism at the onset of heart failure.
Age, Specimen part, Disease, Treatment
View SamplesHeart failure is a leading cause of cardiovascular mortality with limited options for treatment. We analyzed whether the anti-ischemic drug ranolazine could retard the progression of heart failure in an experimental model of heart failure induced by 6 months of chronic pressure overload. The study showed that 2 months of ranolazine treatment improved cardiac function of aortic constricted C57BL/6J (B6) mice with symptoms of heart failure as assessed by echocardiography. The microarray gene expression study of heart tissue from failing hearts relative to ranolazine-treated and healthy control hearts identified heart failure-specific genes that were normalized during treatment with the anti-ischemic drug ranolazine.
Up-regulation of the cardiac lipid metabolism at the onset of heart failure.
Age, Specimen part, Disease, Treatment
View SamplesDepletion of cardiac ATP content is a characteristic feature of heart failure in patients and experimental animal models. To analyze the impact of insufficient ATP supply on heart function we inhibited cellular respiration by disulfide poisoning with the mild thiol-blocking agent, cystamine. We chose 4 month-old apolipoprotein E (apoE)-deficient mice, which are highly vulnerable to increased oxygen and ATP demands. After 4 weeks of cystamine treatment (300 mg/kg in drinking water), echocardiography and histology analyses demonstrated that apoE-deficient mice had developed heart failure with cardiac dilation. The microarray gene expression study of heart tissue from cystamine-treated apoE-deficient mice relative to untreated mice confirmed the development of heart failure showing up-regulation heart failure-specific genes by mild thiol-blocking with cystamine.
Up-regulation of the cardiac lipid metabolism at the onset of heart failure.
Age, Specimen part, Disease, Treatment
View SamplesFoxl2 is a forkhead transcription factor expressed only in the female, but not in the male gonad. We have created mice homozygous mutant for the Foxl2 gene (KO) as well as mice carrying a conditional mutant Foxl2 allele (floxed).
Somatic sex reprogramming of adult ovaries to testes by FOXL2 ablation.
Specimen part
View Samples