About 50% of human malignancies exhibit unregulated signalling through the Ras-ERK1/2 (ERK) pathway, as a consequence of activating mutations in members of Ras and Raf families. However, the quest for alternative Ras-ERK pathway-directed therapies is desirable. Upon phosphorylation ERK dimerize. We had previously demonstrated that dimerization is essential for ERK extranuclear but not nuclear signaling. Furthermore, by molecular biology approaches, we showed that specifically inhibiting ERK extranuclear component, by impeding ERK dimerization, is sufficient for curtailing tumor progression. Here, we have identified a small molecule inhibitor for ERK dimerization in vitro and in vivo that, without affecting ERK phosphorylation, prevents tumorigenesis driven by Ras-ERK pathway oncogenes, both in cellular and animal models. Importantly, this compound is unaffected by resistance-acquisition processes that hamper “classical” Ras-ERK pathway inhibitors. Thus, ERK dimerization inhibitors provide the proof of principle for two novel concepts in cancer therapy: 1) The blockade of sublocalization-specific sub-signals, rather than total signals, as a means of effectively counteracting oncogenic Ras-ERK signaling. 2) Targeting regulatory protein-protein interactions such as dimerization, rather than catalytic activities, within a signaling route, as an approach for producing effective anti-tumoral agents. Strategies aimed at preventing aberrant flux through this route remain an attractive option for therapeutic intervention in cancer. In this respect, drugs inhibiting the kinase activities of BRaf and MEK have yielded promising results. Overall design: A375p cells treated with10 µM of either DEL22379, SCH772984 or DMSO as a control for two hours. mRNA from A375p cells was extrated using RNeasy mini kit (Qiagen, Germany) according to the manufacturer''s instructions. Cells were previously treated with10 µM of either DEL22379, SCH772984 or DMSO as a control for two hours.
Small Molecule Inhibition of ERK Dimerization Prevents Tumorigenesis by RAS-ERK Pathway Oncogenes.
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View SamplesPluripotent cell identity comprises a spectrum of cell states including naive and primed states, which are typified by mouse embryonic stem cells (ESCs) and epiblast-derived stem cells (EpiSCs), respectively. Here we define a pluripotent cell fate (PCF) gene signature based on RNA-seq analysis associated with naive and primed pluripotency acquisition, and identify Zfp281 as a key transcriptional regulator for primed pluripotency and also as a barrier to achieve the naive pluripotency of both mouse and human ESCs. Overall design: RNA sequencing analysis was performed in WT and Zfp281 null mouse embryonic stem cells under different pluripotent culture conditions. RNA-seq Experiments were carry out in two biological replciates. Genome binding/occupancy profiling of Zfp281 was performed in mouse embryonic stem cells by ChIP sequencing.
Zfp281 Coordinates Opposing Functions of Tet1 and Tet2 in Pluripotent States.
Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Methyl-CpG-binding protein MBD2 plays a key role in maintenance and spread of DNA methylation at CpG islands and shores in cancer.
Cell line
View SamplesContext: Polycystic ovarian syndrome (PCOS), the most common endocrine disorder of reproductive- aged women, is associated with systemic low-grade inflammation. Objective: We propose that increased or altered intrafollicular inflammatory reactions also occur in periovulatory follicles of PCOS patients. Design: Gene profiling and quantitative PCR (qPCR) analyses in granulosa-lutein cells (GCs) collected from PCOS and non-PCOS women undergoing in vitro fertilization were compared with serum and follicular fluid (FF) levels of cytokines and chemokines. Setting: This was a university-based study. Patients: Twenty-one PCOS and 45 control patients were recruited: demographic, hormone, body mass index, and pregnancy outcomes were abstracted from patient data files. Interventions:GCcytokine/chemokinemRNAswere identified and analyzed by gene-chip microarrays/ qPCR before and after culture withhumanchorionic gonadotropin, DHT, IL-6, or IL-8; serum/FF cytokine levels were also analyzed. Main Outcome Measures: Relative serum/FF cytokine levels and GC cytokine expression before and after culture were compared and related to body mass index. Results: The following results were found: 1) PCOS GCs express elevated transcripts encoding cytokines, chemokines, and immune cell markers, 2) based on gene profiling and qPCR analyses, obese PCOS patients define a distinct PCOS disease subtype with the most dramatic increases in proinflammatory and immune-related factors, and 3) human chorionic gonadotropin and DHT increased cytokine production in cultured GCs, whereas cytokines augmented cytokine and vascular genes, indicating that hyperandrogenism/elevated LH and obesity in PCOS women augment intrafollicular cytokine production. Conclusions: Intrafollicular androgens and cytokines likely comprise a local regulatory loop that impacts GC expression of cytokines and chemokines and the presence of immune cells; this loop is further enhanced in the obese PCOS subtype.
Enhanced Inflammatory Transcriptome in the Granulosa Cells of Women With Polycystic Ovarian Syndrome.
Specimen part
View SamplesCancer is characterised by DNA hypermethylation and gene silencing of CpG island-associated promoters, including tumour suppressor genes The methyl-CpG-binding domain (MBD) family of proteins bind to methylated DNA and can aid in the meditation of gene silencing by interaction with histone deacetylases and histone methyltransferases. However the mechanisms responsible for eliciting CpG island hypermethylation in cancer, and the potential role that MBD may proteins play in modulation of the methylome remain unclear. Our previous work demonstrated that MBD2 preferentially binds to the hypermethylated GSTP1 promoter CpG island in prostate cancer cells. Here, we use functional genetic approaches to investigate if MBD2 plays an active role in promoting DNA methylation. First, we show that loss of MBD2 results in inhibition of both maintenance and spread of de novo methylation of a transfected construct containing the GSTP1 promoter CpG island in prostate cancer cells and Mbd2-/- mouse fibroblasts. De novo methylation was rescued by transient expression of Mbd2 in Mbd2-/- cells. Second, we show that MBD2 depletion triggers significant hypomethylation genome-wide in prostate cancer cells with concomitant loss of MBD2 binding at promoter and enhancer regulatory regions. Finally, CpG islands and shores that become hypomethylated after MBD2 depletion in LNCaP cancer cells show significant hypermethylation in clinical prostate cancer, highlighting a potential active role of MBD2 in promoting cancer specific hypermethylation. Importantly, co-immunoprecipiation of MBD2 reveals that MBD2 associates with DNA methyltransferase (DNMT) enzymes 1 and 3A. Together our results demonstrate that MBD2 plays a critical role in rewriting the cancer methylome at specific regulatory regions.
Methyl-CpG-binding protein MBD2 plays a key role in maintenance and spread of DNA methylation at CpG islands and shores in cancer.
Cell line
View SamplesHepatitis B virus (HBV) infection is a major health problem worldwide and chronically infected individuals are at high risk of developing cirrhosis and hepatocellular carcinoma (HCC). The molecular mechanisms whereby HBV causes HCC are largely unknown. By using a biologically relevant system of HBV infection of primary human hepatocytes (PHHs), we studied how HBV perturbs gene expressions and signaling pathways of infected hepatocytes, and whether these effects are relevant to productive HBV infection and HBV-associated HCC. Using a human growth factor antibody array, we first showed that HBV infection induced a distinct profile of growth factor production by PHHs, marked particularly by significantly lower levels of transforming growth factor (TGF)- family of proteins in the supernatant. Transcriptome profiling next revealed multiple changes in cell proliferation and cell cycle control pathways in response to HBV infection. A human cell cycle PCR array validated deregulation of more than 20 gene associated with cell cycle in HBV-infected PHHs. Cell cycle analysis demonstrated that HBV-infected PHHs are enriched in the G2/M phase as compared to the predominantly G0/G1 phase of cultured PHHs. HBV proviral host factors, such as PPARA, RXRA and CEBPB, were up-regulated upon HBV infection and particularly enriched in cells at the G2/M phase. Together, these results support that HBV deregulates cell cycle control to render a cellular environment that is favorable for productive HBV infection. By perturbing cell cycle regulation of infected cells, HBV may coincidently induce a premalignant phenotype that predispose infected hepatocytes to subsequent malignant transformation.
Hepatitis B Virus Deregulates the Cell Cycle To Promote Viral Replication and a Premalignant Phenotype.
Specimen part
View SamplesIn the present study, we aimed to define the role of VDR in the overall lipid metabolism by transcriptomic and metabolomic analyses of human hepatocytes upon VDR activation by vitamin D (VitD)
The Vitamin D Receptor Regulates Glycerolipid and Phospholipid Metabolism in Human Hepatocytes.
Specimen part, Cell line, Treatment
View SamplesHost cells harbor various intrinsic mechanisms to restrict viral infections as a first line of antiviral defense. Viruses have evolved various countermeasures against these antiviral mechanisms. Here we show that N-Myc Downstream-Reguated Gene 1 (NDRG1) limits productive HCV infection by inhibiting viral assembly. Interestingly, HCV infection down-regulates NDRG1 protein and mRNA expression. Loss of NDRG1 increases the size and number of lipid droplets, which are the sites of HCV assembly. HCV suppresses NDRG1 expression by up-regulating MYC, which directly inhibits the transcription of NDRG1.
N-Myc Downstream-Regulated Gene 1 Restricts Hepatitis C Virus Propagation by Regulating Lipid Droplet Biogenesis and Viral Assembly.
Cell line, Treatment
View SamplesSIRT1 deacetylase functions in a variety of cells and tissues to mitigate age- and disease-induced damages. However, it remains unknown if SIRT1 also acts to prevent pathological changes that accrue in motor units, and specifically alpha-motor neurons, with advancing age and during the progression of amyotrophic lateral sclerosis (ALS). Here, we show that SIRT1 expression decreases in the spinal cord of wild type mice with advancing age. Using mouse models that overexpress or inactivate SIRT1 in motor neurons, we discovered that SIRT1 prevents age-related degeneration of motor neurons' presynaptic sites at neuromuscular junctions (NMJs). We also found that increasing SIRT1 in motor neurons delays degeneration of presynaptic sites at NMJs and extends the lifespan of SOD1G93A mice. Thus, SIRT1 has a similar effect on aging and ALS-affected motor neurons, two conditions in which a remarkable number of transcripts are similarly altered in the spinal cord. These include genes involved in inflammatory and immune responses and genes with known function at synapses. These findings show that SIRT1 functions to mitigate pathological changes induced by aging and ALS, two conditions with a surprising degree of overlap in the spinal cord. Overall design: Eight replicates spinal cords from mice aged 18-24 months, eight replicates of spinal cords from mice aged 3-4 months, 3 replicates of spinal cords from ALS symptomatic mice aged 5-6 months and 3 replicates of spinal cords from wt controls aged 5-6 months.
SIRT1 deacetylase in aging-induced neuromuscular degeneration and amyotrophic lateral sclerosis.
Cell line, Subject
View SamplesChlamydia trachomatis is an obligate intracellular pathogen that causes trachoma and sextually transmitted disease in human. During early stage of infection, Chlamydia secreted bacterial effector proteins into host cell cytoplasm to help its entry and estabilishment of early replicated niche.
The Chlamydia trachomatis type III secretion chaperone Slc1 engages multiple early effectors, including TepP, a tyrosine-phosphorylated protein required for the recruitment of CrkI-II to nascent inclusions and innate immune signaling.
Specimen part, Cell line, Time
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