A quantitative genetic analysis of the yeast replicative life span was carried out by sampling the natural genetic variation
Natural genetic variation in yeast longevity.
No sample metadata fields
View SamplesA number of key regulators of mouse embryonic stem (ES) cell identity, including the transcription factor Nanog, show strong expression fluctuations at the single cell level. The molecular basis for these fluctuations is unknown. Here we used a genetic complementation strategy to investigate expression changes during transient periods of Nanog downregulation. Employing an integrated approach, that includes high-throughput single cell transcriptional profiling and mathematical modelling, we found that early molecular changes subsequent to Nanog loss are stochastic and reversible. However, analysis also revealed that Nanog loss severely compromises the self-sustaining feedback structure of the ES cell regulatory network. Consequently, these nascent changes soon become consolidated to committed fate decisions in the prolonged absence of Nanog. Consistent with this, we found that exogenous regulation of Nanog-dependent feedback control mechanisms produced more a homogeneous ES cell population. Taken together our results indicate that Nanog-dependent feedback loops play a role in controlling both ES cell fate decisions and population variability.
Nanog-dependent feedback loops regulate murine embryonic stem cell heterogeneity.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Epigenetic drug combination induces genome-wide demethylation and altered gene expression in neuro-ectodermal tumor-derived cell lines.
Sex, Specimen part, Disease, Cell line, Treatment
View SamplesAbstract: Epigenetic alterations are a fundamental aspect of cancer cells, and epigenetic drugs are currently used in clinical practice for hematological malignancies. Pediatric neuro-ectodermal tumors originate from neural crest cells and show epigenetic defects of apoptotic pathways, which makes the introduction of epigenetic drugs in this patient category logical. However, the young age of these patients is accompanied by ongoing developmental processes which are regulated epigenetic mechanisms, and prompted us to study molecular effects of nanomolar dosage epigenetic drugs in neuro-ectodermal tumor cell lines. Combination treatment of 5-aza-2`-deoxicytidine (DAC) and Trichostatin A (TSA) at nanomolar dosages resulted in wide-spread demethylating effects in 17 NBL and 5 PNET cell lines in vitro. This widespread demethylation had large effects on gene-expression profiles. In NBL cell lines, almost every cellular pathway (193/200) investigated demonstrated altered expression upon treatment, and resulted in upregulation of known epigenetically regulated genes such as X-chromosomal, tissue-specific, and a few imprinted genes. Integration analysis of CpG island methylation array data and whole genome gene expression data identified 30 genes potentially upregulated by gene promoter demethylation. Homeobox genes frequently showed demethylation in both short term (72 hours) and long term cultures (3 months) of NBL lines. Continuous treatment with epigenetic drugs resulted in low rates of proliferation. The low rate of proliferation that might explain limited consecutive demethylation upon prolonged exposure. In conclusion, genome-wide methylation and gene expression changes are induced DAC and TSA treatment at nanomolar dosages. These effects affected more than 97% of cellular pathways investigated. Further studies towards the effects of epigenetic drug combinations are advised before being applied in clinical trials for pediatric patients.
Epigenetic drug combination induces genome-wide demethylation and altered gene expression in neuro-ectodermal tumor-derived cell lines.
Sex, Specimen part, Cell line
View SamplesAcute Lymphoblastic Leukemia (ALL) in infants (<1 year) is characterized by a poor prognosis and a high incidence of MLL translocations. Several studies demonstrated the unique gene expression profile associated with MLL-rearranged ALL, but generally small cohorts were analyzed as uniform patient groups regardless of the type of MLL translocation, while the analysis of translocation-negative infant ALL remained unacknowledged.
Gene expression profiling-based dissection of MLL translocated and MLL germline acute lymphoblastic leukemia in infants.
Sex, Age, Specimen part
View SamplesTristetraprolin (TTP) is a tandem CCCH zinc finger protein that was identified through its rapid induction by mitogens in fibroblasts. Studies of TTP-deficient mice, and cells derived from them, showed that TTP could bind to certain AU-rich elements in mRNAs, leading to increases in the rates of mRNA deadenylation and destruction. Known physiological target
Novel mRNA targets for tristetraprolin (TTP) identified by global analysis of stabilized transcripts in TTP-deficient fibroblasts.
Cell line
View SamplesThe ZFP36L3 protein is a rodent-specific, placenta- and yolk sac-specific member of the tristetraprolin (TTP) family of CCCH tandem zinc finger proteins. These proteins bind to AU-rich elements in target mRNAs, and promote their deadenylation and decay. Mice deficient in ZFP36L3 exhibited decreased neonatal survival rates, but no apparent morphological changes in the placenta or surviving offspring. Zfp36l3 is paternally imprinted, with profound parent-of-origin effects on gene expression. RNASeq of KO placental mRNA revealed many significantly affected transcripts, some of which exhibited decreased decay rates in differentiated trophoblast stem cells derived from KO blastocysts. The type 1 transferrin receptor mRNA was unexpectedly decreased in KO placentas, despite an increase in its stability. This receptor is critical for placental iron uptake from the maternal circulation, and its decrease was accompanied by decreased iron stores in the KO fetus, suggesting that this intrauterine deficiency might have deleterious consequences in later life. Overall design: Examination of gene expression differences in yolk sac tissue between wild-type and knockout mice groups with 4 biological replicates in each group
Deficiency of the placenta- and yolk sac-specific tristetraprolin family member ZFP36L3 identifies likely mRNA targets and an unexpected link to placental iron metabolism.
No sample metadata fields
View SamplesZFP36L2, zinc finger protein 36, C3H type-like 2 (also known as Brf2, Erf2, Tis11D) is a member of the tristetraprolin (TTP; Zfp36) family of tandem CCCH zinc finger proteins that can bind to AU-rich elements (AREs) in the 3'-untranslated region of mRNAs, leading to their deadenylation and subsequent degradation. We have generated Zfp36l2 knockout mice. Knockout mice were born at the expected Mendelian frequency, but within several weeks of birth they died rather suddenly with pallor and frequent intestinal hemorrhage. These mice exhibited pancytopenia, decreased hematopoietic progenitor cells from fetal liver and yolk sac, and ineffective hematopoietic stem cells. Since ZFP26L2 is likely to function as an ARE-containing mRNA destabilizing protein, we were interested in identifying any abnormally stabilized transcripts in fetal livers from the Zfp36l2 knockout mice whose protein product may directly or indirectly affect hematopoietic stem cell function.
Targeted disruption of Zfp36l2, encoding a CCCH tandem zinc finger RNA-binding protein, results in defective hematopoiesis.
Specimen part
View SamplesWe used microarrays to detail the global gene expression changes following apical infection of porcine choroid plexus epithelial cells (PCPEC) with Streptococcus suis (S. suis)
In vitro transcriptome analysis of porcine choroid plexus epithelial cells in response to Streptococcus suis: release of pro-inflammatory cytokines and chemokines.
Specimen part
View SamplesTankyrases (TNKS) play roles in Wnt signaling, telomere homeostasis and mitosis, offering attractive targets for anti-cancer treatment. Using unbiased combination screening in a large panel of cancer cell lines, we have identified a strong synergy between TNKS and MEK inhibitors in KRAS mutant cancer cells. Our study uncovers a novel function of TNKS in the relief of a feedback loop induced by MEK inhibition on FGFR2 signaling pathway. Moreover, dual inhibition of TNKS and MEK leads to more robust apoptosis and anti-tumor activity both in vitro and in vivo than effects observed by previously reported MEK inhibitor combinations. Altogether, our results show how a novel combination of TNKS and MEK inhibitors can be highly effective in targeting KRAS mutant cancers by suppressing a newly discovered resistance mechanism.
Inhibiting Tankyrases sensitizes KRAS-mutant cancer cells to MEK inhibitors via FGFR2 feedback signaling.
Cell line, Treatment
View Samples