Using an in vitro model for malignant transformation of human bronchial epithelial cells (HBECs) we have found epithelial-to-mesenchymal transition (EMT) and expression of the EMT-transcription factor ZEB1 are early and critical events. Specifically, we found preexisting oncogenic mutations in TP53 and KRAS were required for HBECs to engage EMT machinery in response to microenvironmental (serum/TGF) or specific oncogenetic (MYC) EMT-inducing factors, which induce EMT through distinct TGF-dependent and vitamin D receptor (VDR)-dependent pathways, respectively, with both requiring ZEB1. Functional studies demonstrated ZEB1 causally promotes the malignant progression of HBECs and tumorigenicity of NSCLC and small cell lung cancer (SCLC) lines. Mechanistically ZEB1 directly represses ESRP1 leading to increased mesenchymal splicing of CD44, which drives a switch to CD44hi status and defines a highly transformed subpopulation. This was supported by finding ZEB1 is expressed in early-stage primary non-small cell lung cancers (NSCLC), as early as stage IB tumors, and its expression correlates with TNM stage. We conclude that: ZEB1-induced EMT and associated ESRP1 and CD44 molecular changes are important biomarkers for lung cancer pathogenesis; TGF and VDR are EMT chemoprevention targets; and as such, ZEB1 represents an important therapeutic target in NSCLC and SCLC.
ZEB1 drives epithelial-to-mesenchymal transition in lung cancer.
Sex, Age, Cell line
View SamplesTransgenic animals were engineered to express human amyloid peptide controlled by a muscle-specific, heat-inducible promoter. At low temperatures (16C) Abeta expression is minimal, while at higher temperatures (20-25C) Abeta accummulates in large quantities and causes paralysis.
Identifying Aβ-specific pathogenic mechanisms using a nematode model of Alzheimer's disease.
Time
View SamplesThe Melanoma-associated Antigen gene family (MAGE) generally encodes for tumour antigens. We recently have identified one of the MAGE gene members, Mageb16 to be highly expressed in undifferentiated murine embryonic stem cells (mESCs). The role of Mageb16 for the differentiation of the pluripotent stem cells is completely unknown. Here we demonstrate that Mageb16 (41 kDa) is distributed in cytosol and/or in surface membrane in undifferentiated mESCs. A transcriptome study was performed with differentiated short hairpin RNA (shRNA)-mediated Mageb16 knockdown (KD ESCs) and scrambled control (SCR) ESCs until a period of 22 days. Mageb16 KD ESCs mainly differentiated towards mesodermal derivatives such as cardiovascular lineages. Mesoderm-oriented differentiation initiated biological processes such as adipogenesis, osteogenesis, limb morphogenesis and spermatogenesis were significantly enriched in the differentiated Mageb16 KD ESCs. Cardiomyogenesis in differentiated KD mESCs was stronger when compared to differentiated SCR and wild mESCs. The expression of non-coding RNA (ncRNA) Lin28a and other epigenetic regulatory genes, nucleocytoplasmic trafficking and genes participating in spermatogenesis have also declined faster in the differentiating Mageb16 KD ESCs. We conclude that Mageb16 plays a crucial role for differentiation of ESCs, specifically to the mesodermal lineages. Regulative epigenetic networks and nucleocytoplasmic modifications induced by Mageb16 may play a role for the critical role of Mageb16 for the ESCs differentiation.
Depletion of Mageb16 induces differentiation of pluripotent stem cells predominantly into mesodermal derivatives.
Sex, Specimen part
View SamplesICU acquired weakness (ICUAW) is a complication of critical illness characterized by structural and functional impairment of skeletal muscle that may persist for years after ICU discharge with many survivors developing protracted courses with few regaining functional independence. Elucidating molecular mechanisms underscoring sustained ICUAW is crucial to understanding outcomes linked to different morbidity trajectories as well as for the development of novel therapies. Quadriceps muscle biopsies and functional measures of muscle strength and mass were obtained at 7 days and 6 months post-ICU discharge from a cohort of ICUAW patients. Unsupervised co-expression network analysis of transcriptomic profiles identified discrete modules of co-expressed genes associated with the degree of muscle weakness and atrophy in early and sustained ICUAW. Modules were enriched for genes involved in skeletal muscle regeneration and extracellular matrix deposition. Collagen deposition in persistent ICUAW was confirmed by histochemical stain. Modules were further validated in an independent cohort of critically ill patients with sepsis-induced multi-organ failure and a porcine model of ICUAW, demonstrating disease-associated conservation across species and peripheral muscle type. Our findings provide a pathomolecular basis for sustained ICUAW, implicating aberrant expression of distinct skeletal muscle structural and regenerative genes in early and persistent ICUAW.
Transcriptomic analysis reveals abnormal muscle repair and remodeling in survivors of critical illness with sustained weakness.
Sex, Age
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Pausing of RNA polymerase II disrupts DNA-specified nucleosome organization to enable precise gene regulation.
Specimen part
View SamplesComparative analysis of Endodermal-like cell lines with demonstrated ability to support myocardial differentiation
A comparative analysis of extra-embryonic endoderm cell lines.
Specimen part
View SamplesMetazoan transcription is controlled through either coordinated recruitment of transcription machinery to the gene promoter, or subsequently, through regulated pausing of RNA polymerase II (Pol II) in early elongation. We report that a key difference between genes that use these distinct regulatory strategies lies in the chromatin architecture specified by their DNA sequences. Pol II pausing is prominent at highly-regulated genes whose sequences inherently disfavor nucleosome formation within the gene, but favor nucleosomal occlusion of the promoter. Pausing of polymerase maintains these genes in an active state by inhibiting the formation of repressive promoter chromatin. In contrast, promoters of housekeeping genes that lack paused Pol II are deprived of nucleosomes regardless of polymerase binding, but show higher nucleosome occupancy downstream. Our results suggest that the default chromatin state of a gene instructs its regulation, and that highly-regulated promoters have evolved to encourage competition between nucleosomes and paused Pol II for promoter occupancy.
Pausing of RNA polymerase II disrupts DNA-specified nucleosome organization to enable precise gene regulation.
Specimen part
View SamplesDengue is one of the most important arboviruses in the world, with 2.5 billion people living in areas under risk to contagious. Mosquitos from Aedes genus is the transmission vector of viral particles.
Single point mutations in the helicase domain of the NS3 protein enhance dengue virus replicative capacity in human monocyte-derived dendritic cells and circumvent the type I interferon response.
Specimen part, Time
View SamplesThe response of drosophila to bacterial and fungal infections involves two signaling pathways, Toll and Imd, which both activate NF-kB family members. We have studied the global transcriptional response of flies to infection with drosophila C virus. Viral infection induced a set of genes distinct from those regulated by the Toll or Imd pathways, and triggered activation of a STAT binding activity. Genetic experiments showed that the JAK kinase Hopscotch was involved in the control of the viral load in infected flies, and was required, though not sufficient, for the induction of some virus-regulated genes. Our results indicate that in addition to Toll and Imd, a third evolutionary conserved innate immunity pathway operates in drosophila and counters viral infection.
The Jak-STAT signaling pathway is required but not sufficient for the antiviral response of drosophila.
No sample metadata fields
View SamplesWe used microarrays to investigate gene expression changes induced by the inhibition of RRAS2 expression using shRNA techniques to stably knockdown the endogenous transcripts of this GTPase in human MDA-MB-231-Luc cells.
Contribution of the R-Ras2 GTP-binding protein to primary breast tumorigenesis and late-stage metastatic disease.
Cell line
View Samples