The molecules RhoC and RhoA are essential factors for invasion/metastasis of tumor cells proliferation, respectively. RhoC over-expression was especially linked to aggressive cancers, which requires loss of epithelial polarity and deregulation of cellular adhesion. This epithelial-mesenchymal transition (EMT) includes a change in gene expression pattern through several transcription factors, like Snail, ZEB1 or Twist. Here we analyze the potential of RhoC to induce EMT, migration and invasion and to regulate specific genes involved in tumorigenesis. We established stable MCF-10A cell lines with RhoA/RhoC expression under the control of a doxycycline-regulated trans-activator and a transcriptional silencer allowing conditional expression of RhoA and RhoC, respectively. We additionally quantified the transcriptional response from two bacterial toxins: Escherichia coli Cytotoxic Necrotizing Factor 1 (CNF1) and Yersinia pseudotuberculosis Cytotoxic Necrotizing Factor (CNFY) to directly activate the endogenous pool of Rho GTPases and characterized changes in morphology, migration and invasion upon induction of RhoA/RhoC expression or activation by the toxins in MCF-10A grown in two- and three-dimensions. The transcriptome response identified PTGS2 as RhoC specific target genes involved in pro-migratory changes which was experimentally validated.
Specific role of RhoC in tumor invasion and metastasis.
Cell lineView Samples
Human intervention study with two doses of iron (as ferrous gluconate via intestinal perfusion) to study the effect on genome-wide gene expression in the small intestine, in order to obtain detailed information about intestinal transcriptomics in vivo.
Gene expression in human small intestinal mucosa in vivo is mediated by iron-induced oxidative stress.
Sex, Disease, Disease stage, SubjectView Samples
Probiotic bacteria, specific representatives of bacterial species that are a common part of the human microbiota, are proposed to deliver health benefits to the consumer by modulation of intestinal function via largely unknown molecular mechanisms. To explore in vivo mucosal responses of healthy adults to probiotics, we obtained transcriptomes in an intervention study following a double-blind placebo-controlled cross-over design. In the mucosa of the proximal small intestine of healthy volunteers, probiotic strains from the species Lactobacillus acidophilus, L. casei and L. rhamnosus each induced differential gene regulatory networks and pathways in the human mucosa. Comprehensive analyses revealed that these transcriptional networks regulate major basal mucosal processes, and uncovered remarkable similarity to response profiles obtained for specific bioactive molecules and drugs. This study elucidates how intestinal mucosa of healthy humans perceive different probiotics and provides avenues for rationally designed tests of clinical applications.
Human mucosal in vivo transcriptome responses to three lactobacilli indicate how probiotics may modulate human cellular pathways.
Specimen partView Samples
Some commensal bacteria stimulate the immune system but do not present specific antigenicity. Such adjuvant effects have been reported for the bacterial species Lactobacillus plantarum. To study in vivo human responses to L. plantarum, a randomised double-blind placebo-controlled cross-over study was performed. Healthy adults were provided preparations of living and heat-killed L. plantarum bacteria, biopsies were taken from the intestinal mucosa and altered transcriptional profiles were analysed. Transcriptional profiles of human epithelia displayed striking differences upon exposure to living L. plantarum bacteria harvested at different growth phases. Modulation of NF-B-dependent pathways was central among the major altered cellular responses. This unique in vivo study shows which cellular pathways are associated with the induction of immune tolerance in mucosal tissues towards common adjuvanticity possessing lactobacilli.
Differential NF-kappaB pathways induction by Lactobacillus plantarum in the duodenum of healthy humans correlating with immune tolerance.
No sample metadata fieldsView Samples
The spatial organization of chromosomes influences many nuclear processes including gene expression. The cohesin complex shapes the 3D genome by looping together CTCF sites along chromosomes. We show here that chromatin loop size can be increased, and that the duration with which cohesin embraces DNA determines the degree to which loops are enlarged. Cohesin's DNA release factor WAPL restricts the degree of this loop extension and also prevents looping between incorrectly oriented CTCF sites. We reveal that the SCC2/SCC4 complex promotes the extension of chromatin loops and the formation of topologically associated domains (TADs). Our data support the model that cohesin structures chromosomes through the processive enlargement of loops and that TADs reflect polyclonal collections of loops in the making. Finally, we find that whereas cohesin promotes chromosomal looping, it rather limits nuclear compartmentalization. We conclude that the balanced activity of SCC2/SCC4 and WAPL enables cohesin to correctly structure chromosomes. Overall design: RNAseq was performed in control, ?WAPL 3.3, ?WAPL 1.14, ?SCC4 and ?WAPL/?SCC4 cells in triplicate.
The Cohesin Release Factor WAPL Restricts Chromatin Loop Extension.
Cell line, SubjectView Samples
This SuperSeries is composed of the SubSeries listed below.
ELF5 suppresses estrogen sensitivity and underpins the acquisition of antiestrogen resistance in luminal breast cancer.
Cell line, Treatment, TimeView Samples
We used genome-wide expression analyses to study the response of Saccharomyces cerevisiae to stress throughout a 15-day wine fermentation. Forty percent of the yeast genome significantly changed expression levels to mediate long-term adaptation to an environment in which ethanol is both a stressor and a carbon source. Within this set, we identify a group of 223 genes, designated as the Fermentation Stress Response (FSR), that are dramatically and permanently induced; FSR genes exhibited changes ranging from four-to eighty-fold. The FSR is novel; 62% of the genes involved have not been implicated in global stress responses and 28% of the genes have no functional annotation. Genes involved in respiratory metabolism and gluconeogenesis were expressed during fermentation despite the presence of high concentrations of glucose. Ethanol, rather than nutrient depletion, was responsible for entry of yeast cells into stationary phase. Ethanol seems to regulate yeast metabolism through hitherto undiscovered regulatory networks during wine fermentation.
Dynamics of the yeast transcriptome during wine fermentation reveals a novel fermentation stress response.
No sample metadata fieldsView Samples
Imatinib has become the current standard therapy for patients with chronic myelogenous leukaemia (CML). For a better understanding of the Imatinib-related molecular effects in vivo, we assessed gene expression profiles of Philadelphia Chromosome positive (Ph+) CD34+ cells from peripheral blood of 6 patients with de novo CML in chronic phase. After 7 days of treatment with Imatinib the Ph+ CD34+ cells were reassessed to look for changes in the transcriptome. The expression level of 303 genes was significantly different comparing the transcriptome of the Ph+ CD34+ cells before and after 7 days of Imatinib therapy (183 down-regulated, 120 up-regulated, lower bound 1.2-fold). For a substantial number of genes governing cell cycle and DNA replication, the level of expression significantly decreased (CDC2, RRM2, PCNA, MCM4). On the other hand, therapy with Imatinib was associated with an increase of genes related to adhesive interactions, such as L-selectin or CD44. A group of 8 genes with differential expression levels were confirmed using a gene specific quantitative real-time PCR. Thus, during the first week of treatment, Imatinib is preferentially counteracting the bcr-abl induced effects related to a disturbed cell cycle and defective adhesion of leukemic Ph+ CD34+ cells.
Early in vivo changes of the transcriptome in Philadelphia chromosome-positive CD34+ cells from patients with chronic myelogenous leukaemia following imatinib therapy.
No sample metadata fieldsView Samples
The reprogramming of somatic cells into induced pluripotent stem cells (iPSCs) upon overexpression of OCT4, KLF4, SOX2 and c-MYC (OKSM) provides a powerful system to interrogate basic mechanisms of cell fate change. However, iPSC formation with standard methods is typically protracted and inefficient, resulting in heterogeneous cell populations. We show that exposure of OKSM-expressing cells to both ascorbic acid and a GSK3- inhibitor (AGi) facilitates more synchronous and rapid iPSC formation from several mouse cell types. AGi treatment restored the ability of refractory cell populations to yield iPSC colonies, and it attenuated the activation of developmental regulators commonly observed during the reprogramming process. Moreover, AGi supplementation gave rise to chimera-competent iPSCs after as little as 48 h of OKSM expression. Our results offer a simple modification to the reprogramming protocol, facilitating iPSC induction at unparalleled efficiencies and enabling dissection of the underlying mechanisms in more homogeneous cell populations.
Small molecules facilitate rapid and synchronous iPSC generation.
Specimen part, Treatment, TimeView Samples
Brief expression of pluripotency-associated factors such as Oct4, Klf4, Sox2 and c-Myc (OKSM), in combination with differentiation-inducing signals, has been reported to trigger transdifferentiation of fibroblasts into other cell types. Here we show that OKSM expression in mouse fibroblasts gives rise to both induced pluripotent stem cells (iPSCs) and induced neural stem cells (iNSCs) under conditions previously shown to induce only iNSCs. Fibroblast-derived iNSC colonies silenced retroviral transgenes and reactivated silenced X chromosomes, both hallmarks of pluripotent stem cells. Moreover, lineage tracing with an Oct4-CreER labeling system demonstrated that virtually all iNSC colonies originated from cells transiently expressing Oct4, whereas ablation of Oct4+ cells prevented iNSC formation. Lastly, an alternative transdifferentiation cocktail that lacks Oct4 and was reportedly unable to support induced pluripotency yielded iPSCs and iNSCs carrying the Oct4-CreER-derived lineage label. Together, these data suggest that iNSC generation from fibroblasts using OKSM and other pluripotency-related reprogramming factors requires passage through a transient iPSC state.
Lineage conversion induced by pluripotency factors involves transient passage through an iPSC stage.
Sex, Specimen partView Samples