Cancer stem cells (CSCs) are plastic in nature, a characteristic that hampers cancer therapeutics. Neuroblastoma (NB) is a pediatric tumor of neural crest origin, and half of the cases are highly aggressive. By treating NB cell lines (SKNAS, SKNBE(2)C, CHP134, SY5Y) with epigenetic modifiers for a short time followed by sphere-forming culture conditions, we have established stem cell-like NB cells that are phenotypically stable for over a year. These cells are characterized by their high expression of stemness factors, stem cell markers, and open chromatin structure. We referred to these cells as induced CSC (iCSC). SKNAS iCSC and SKNBE(2)C iCSC clones (as few as 100 cells) injected subcutaneously into SCID/Beige mice formed tumors, and in one case, SKNBE(2)C iCSC metastasized to the adrenal gland, suggesting their increased metastatic potential. SKNAS iCSC xenografts showed the histologic appearance of totally undifferentiated large-cell NBs (LCNs), the most aggressive and deadly form of NB in humans. Immunohistochemical analyses showed that SKNAS iCSC xenografts expressed high levels of the stem cell marker CXCR4, while the SKNAS monolayer cell xenografts did not. The patterns of CXCR4 and MYC expression in SKNAS iCSC xenografts resembled those in the LCNs. The xenografts established from the NB iCSCs shared two common features: the LCN phenotype and high-level MYC/MYCN expression. These observations suggest that NB cells with large and vesicular nuclei, representing their open chromatin structure, are indicative of stem cell-like tumor cells, and that epigenetic changes may have contributed to the development of these most malignant NB cells.
Transient treatment with epigenetic modifiers yields stable neuroblastoma stem cells resembling aggressive large-cell neuroblastomas.
No sample metadata fields
View SamplesRemodeling of the actin cytoskeleton through actin dynamics (assembly and disassembly of filamentous actin) is known to be essential for numerous basic biological processes. In addition, recent in vitro studies provided evidence that actin dynamics participate in the control of gene expression. A spontaneous mouse mutant, corneal disease 1 (corn1), is deficient for a regulator of actin dynamics, destrin (DSTN; also known as actin depolymerizing factor or ADF), and develops epithelial hyperproliferation and neovascularization in the cornea. Dstncorn1 mice exhibit the actin dynamics defect in the corneal epithelial cells as evidenced by increased filamentous actin, offering an in vivo model to investigate the physiological significance of the transcriptional regulation by actin dynamics. To examine the effect of the Dstncorn1 mutation on gene expression, we performed a microarray analysis using the cornea from Dstncorn1 and wild-type control mice. A dramatic alteration of gene expression was observed in the Dstncorn1 cornea, with 1,226 annotated genes differentially expressed. Functional annotation of these genes revealed that most significantly enriched functional categories are associated with actin and/or cytoskeleton. Among genes that belong to these categories, a considerable number of serum response factor (SRF) target genes were found, indicating the existence of the actin-SRF pathway of transcriptional regulation in vivo. A comparative study using an allelic mutant strain, Dstncorn1-2J, with milder corneal phenotypes also suggested that the severity of the actin dynamics defect correlates with the level of gene expression changes. Our study provides evidence that actin dynamics have a strong impact on gene expression in vivo.
Effect of destrin mutations on the gene expression profile in vivo.
Sex, Age
View SamplesThe purpose of this study is to characterize gene expression changes that occur when conditional knock-out of Srf rescues mutant phenotypes in the cornea of Dstncorn1 mice.
Serum response factor: positive and negative regulation of an epithelial gene expression network in the destrin mutant cornea.
Specimen part
View SamplesIn the present study, we hypothesized that C/EBPa (CCAAT/enhancer-binding protein alpha) plays a role in cell regeneration in response to bronchiolar epithelial cell injury. C/EBPa mediated ciliated cell regeneration after naphthalene bronchiolar epithelial cell injury in vivo. Furthermore, we demonstrated that C/EBPa regulates protease/anti-protease balance after lung injury, and intratracheal treatment with anti-protease (BPTI) restored ciliated cell regeneration after naphthalene injury in CebpaD/D mice.
CCAAT/enhancer binding protein-α regulates the protease/antiprotease balance required for bronchiolar epithelium regeneration.
Specimen part, Treatment
View SamplesDeletion of Stat3 induced genes influencing protein metabolism, transport, chemotaxis and apoptosis and decreased the expression of genes mediating lipid synthesis and metabolism. Srebf1 and 2, key regulators of fatty acid and steroid biosynthesis, were decreased in Stat3D/D mice. Stat3 influenced both pro- and anti-apoptotic pathways, regulating and maintaining the balance between a subset of pro- and anti-apoptotic genes that determine cell death or survival. Akt, a known target of Stat3, participates in many Stat3 mediated pathways including Jak-Stat signaling, apoptosis, the MAPK signaling, cholesterol and fatty acid biosynthesis. Deletion of Stat3 from type II epithelial cells altered the expression of genes regulating diverse cellular processes, including cell growth and apoptosis, lipid biosynthesis and metabolism. Stat3 regulates cell formation through a complex regulatory network that likely enhances alveolar epithelial cell survival and surfactant/lipid synthesis, necessary for the protection of the lung during injury.
Gene expression and biological processes influenced by deletion of Stat3 in pulmonary type II epithelial cells.
No sample metadata fields
View SamplesWe have previously demonstrated that deletion of the Cebpa gene in the developing fetal mouse lung caused death soon after birth from the failure of lung maturation. Many of the transcriptional pathways regulating morphogenesis of the fetal lung are induced postnatally and mediate repair of the injured lung. We hypothesized that C/EBPa plays a role in protection of the alveolar epithelium following hyperoxia injury of the mature lung. Transgenic Cebpa/ mice in which Cebpa was conditionally deleted from Clara cells (from early gestation) and type II cells (from near-term) were developed. Cebpa/ mice grow normally without any pulmonary abnormalities. Cebpa/ mice were highly susceptible to hyperoxia. Cebpa/ mice died within 4d after hyperoxia associated with severe lung inflammation and altered surfactant components at a time when all control mice survived. Microarrays were analyzed on isolated type II cells at an early stage (24h) of hyperoxia exposure to detect the primary genes influenced by deletion of Cebpa. The associated network analysis revealed the reduced expression of key genes related to surfactant lipid and protein homeostasis, such as Srebf, Scap, Lpcat1, Abca3, Sftpb, and Napsa. Genes for the cell signaling, immune response, and protective antioxidants, including GSH and Vnn-1,3, were decreased in the Cebpa/ mice lung. C/EBPa did not play a critical role in postnatal pulmonary function under normal conditions. In contrast, in the absence of C/EBPa, exposure to hyperoxia caused respiratory failure, supporting the concept that C/EBPa plays an important role in enhancing epithelial cell survival, surfactant lipid homeostasis, and maturation of SP-B from pro-SP-B.
C/EBP{alpha} is required for pulmonary cytoprotection during hyperoxia.
Specimen part
View SamplesAlthough LIPUS has been shown to enhance fracture healing, the underlying mechanism of LIPUS remains to be fully elucidated. Here, to understand the molecular mechanism underlying cellular responses to LIPUS, we investigated gene expression profiles in mouse MC3T3-E1 preosteoblast cells using a GeneChip system.
Genes responsive to low-intensity pulsed ultrasound in MC3T3-E1 preosteoblast cells.
Specimen part, Cell line, Treatment, Time
View SamplesSnail is a transcriptional repressor, which induces epithelial-mesenchymal transition. However, overall functions of Snail remain to be elucidated. This microarray was performed to investigate the influence of Snail expression on mRNA transcription levels in a lung adenocarcinoma cell line, II-18.
Epithelial-mesenchymal transition abolishes the susceptibility of polarized epithelial cell lines to measles virus.
Cell line
View SamplesIn this study, we studied the genomic responses of the Insig and Scap deletion from perinatal lung.
Epithelial SCAP/INSIG/SREBP signaling regulates multiple biological processes during perinatal lung maturation.
Specimen part
View SamplesBackground: Lung function is dependent upon the precise regulation of the synthesis, storage, and catabolism of tissue and alveolar lipids.
Activation of sterol-response element-binding proteins (SREBP) in alveolar type II cells enhances lipogenesis causing pulmonary lipotoxicity.
Specimen part
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