Lineage specific transcription factors (TF) define and reinforce tissue specific cell types. For instance, stable endoderm progenitors were established from human ESC by constitutive expression of SOX7 or SOX17. We hypothesized that combinatorial expression of OCT4, SOX2 and KLF4together with the neural-lineage TF, Zic3, could directly convert fibroblasts into stable neuronal progenitor cells (NPC). Ensuing colonies predominantly expressed genes present in human NPC, as demonstrated by genome wide transcriptional analysis, and this phenotype could be maintained through many passages. When injected in immunodeficient mice, Zic3-induced (Zi)NPC form neuroendocrine tumors without evidence of mesoderm or endoderm. In vitro, ZiNPC spontaneously differentiated to neural cells only, and could be differentiated into astrocytes, oligodendrocytes and motor neuron lineages. In conclusion, addition of Zic3 during induced pluripotent stem cell (iPSC) generation, allows for the derivation of stable neural lineage progenitor cells.
Zic3 induces conversion of human fibroblasts to stable neural progenitor-like cells.
Sex, Specimen part, Disease, Cell line, Treatment
View SamplesThe histological grade of carcinomas describes the ability of tumor cells to organize differentiated epithelial structures and has prognostic impact. Molecular control of differentiation in normal and cancer cells relies on lineage-determining transcription factors (TFs) that activate the repertoire of cis-regulatory elements controlling cell type-specific transcriptional outputs. TF recruitment to cognate genomic DNA binding sites results in the deposition of histone marks characteristic of enhancers and other cis-regulatory elements. Here we integrated transcriptomics and genome-wide analysis of chromatin marks in human pancreatic ductal adenocarcinoma (PDAC) cells of different grade to identify first, and then experimentally validate the sequence-specific TFs controlling grade-specific gene expression. We identified a core set of TFs with a pervasive binding to the enhancer repertoire characteristic of differentiated PDACs and controlling different modules of the epithelial gene expression program. Defining the regulatory networks that control the maintenance of epithelial differentiation of PDAC cells will help determine the molecular basis of PDAC heterogeneity and progression. Overall design: Poly(A) fraction of the total RNA from human pancreatic ductal adenocarcinoma cell lines was extracted and subjected to by multiparallel sequencing. Experiments were carried out in unmodified cells in duplicate, genome edited clonal CFPAC1 cells (2 KLF5-deleted CRISPR-Cas9 clones, 3 ELF3-deleted CRISPR-Cas9 clones and 2 wt clones) and CFPAC1 cells ectopically expressing ZEB1 or empty vector control (in duplicate).
Dissection of transcriptional and cis-regulatory control of differentiation in human pancreatic cancer.
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The histone methyltransferase Wbp7 controls macrophage function through GPI glycolipid anchor synthesis.
Specimen part, Treatment
View SamplesHistone methyltransferases catalyze site-specific deposition of methyl groups, enabling recruitment of transcriptional regulators. In mammals, trimethylation of lysine 4 in histone H3, a modification localized at the transcription start sites of active genes, is catalyzed by six enzymes (SET1a and SET1b, MLL1MLL4) whose specific functions are largely unknown. By using a genomic approach, we found that in macrophages, MLL4 (also known as Wbp7) was required for the expression of Pigp, an essential component of the GPI-GlcNAc transferase, the enzyme catalyzing the first step of glycosylphosphatidylinositol (GPI) anchor synthesis. Impaired Pigp expression in Wbp7-/- macrophages abolished GPI anchor-dependent loading of proteins on the cell membrane. Consistently, loss of GPI-anchored CD14, the coreceptor for lipopolysaccharide (LPS)
The histone methyltransferase Wbp7 controls macrophage function through GPI glycolipid anchor synthesis.
Specimen part, Treatment
View SamplesThe specific ablation of Rb1 gene in stratified epithelia (RbF/F;K14cre) promotes proliferation and altered differentiation but is insufficient to produce spontaneous tumors. The pRb relative, p107, compensates some of the functions of pRb in these tissues, however RbF/F;K14cre;p107-/- mice die postnatally. Acute pRb loss in stratified epithelia, using an inducible mouse model (RbF/F;K14creERTM), shows that p107 exerts specific tumor suppressor functions in its absence. After simultaneous absence of pRb and p107, p53 transcriptional function is impaired and Pten expression is reduced. All mutant mice develop spontaneous squamous tumors carcinomas rapidly. Gene expression analysis of mouse tumors, besides supporting the impaired p53 function and the susceptibility to Akt/mTOR inhibitors, also revealed significant overlap with human squamous carcinomas. Thus, RbF/F;K14creERTM;p107-/- may constitute a new mouse model for these malignancies. Collectively, these data demonstrate the existence of a previously unreported functional connection between pRb, Pten and p53 tumor suppressors, through p107, of a particular relevance in squamous tumor development.
A novel tumor suppressor network in squamous malignancies.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Requirement for the histone deacetylase Hdac3 for the inflammatory gene expression program in macrophages.
Specimen part, Treatment
View SamplesPan-Hdac inhibitors (HDACi) are endowed with a potent anti-inflammatory activity, but the relative role of each of the eleven Hdac proteins sensitive to HDACi to the inflammatory gene expression program is unknown. Using an integrated genomic approach we found that Hdac3-deficient macrophages are unable to activate almost half of the inflammatory gene expression program when stimulated with lipopolysaccharide (LPS). A large part of the activation defect is due to loss of basal and LPS-inducible expression of IFNb, which in basal cells maintains Stat1 protein levels, and after stimulation acts in an autocrine/paracrine manner to promote a secondary wave of Stat1-dependent gene expression. We show that loss of Hdac3-mediated repression of nuclear receptors leads to hyperacetylation of thousands of genomic sites and associated gene derepression. The upregulation of the constitutively expressed prostaglandin endoperoxide synthase, Ptgs1 (Cox-1), has a causative role in the phenotype, since its chemical inhibition reverts the Ifnb activation defect. These data may have relevance for the use of selective Hdac inhibitors as anti-inflammatory agents.
Requirement for the histone deacetylase Hdac3 for the inflammatory gene expression program in macrophages.
Specimen part, Treatment
View SamplesThe enzymes of the poly-ADP-ribose polymerase (PARP) super-family control many relevant cellular processes, but a precise understanding of their activities in different physiological or disease contexts is largely incomplete. We found that transcription of several PARP genes was dynamically regulated upon macrophage activation by several inflammatory stimuli. Specifically, PARP14 was strongly induced by endotoxin stimulation and translocated to the nucleus in stimulated cells. Quantitative mass spectrometry analysis showed that PARP14 bound to a group of interferon-stimulated gene (ISG)-encoded proteins, most with an unknown function, and it was required for their nuclear accumulation. Moreover, PARP14 depletion attenuated transcription of primary antiviral response genes regulated by the transcription factor IRF3, including Ifnb1, thus reducing IFNß production and activation of ISGs involved in the secondary antiviral response. Overall, these data hint at a role of PARP14 in the control of antimicrobial responses and specifically in nuclear activities of a subgroup of ISG-encoded proteins. Overall design: mRNA sequencing of differentially expressed genes in PARP14 WT and KO RAW 264.7 cells, upon: no treatment, LPS, Jak inhibitor or LPS plus Jak inhibitor treatment.
PARP14 Controls the Nuclear Accumulation of a Subset of Type I IFN-Inducible Proteins.
Specimen part, Cell line, Treatment, Subject
View SamplesDuring normal or pathological epithelial-to-mesenchymal transition, epithelium-specific gene expression is shut down, with the DNA-binding factor ZEB1 acting as a master suppressor of epithelial identity. Here, we show that ZEB1 occupies primate-specific tandem repeats (TRs) harboring dozens of copies of its DNA-binding motif and located within genomic loci relevant for epithelial identity. Deletion of one such repeat in a quasi-mesenchymal human cancer cell line induced the reacquisition of epithelial features and phenocopied the effects of ZEB1 gene deletion. Since ZEB1 binds clustered motifs in a non-cooperative manner, changes in its nuclear concentration enable graded adjustments of TR occupancy, thus fine-tuning repression level. In addition, high motif density in TRs allows ZEB1 binding (and shutdown of epithelial programs) despite differences in chromatin organization and accessibility among epithelial cell types. Overall design: Total RNA from human pancreatic ductal adenocarcinoma cell lines was processed for multiparallel sequencing. Experiments were carried out in genome edited clonal MiaPaCa2 cells (3 ZEB1-deleted CRISPR-Cas9 clones and 3 wt clones).
Co-optation of Tandem DNA Repeats for the Maintenance of Mesenchymal Identity.
Cell line, Subject
View SamplesThe enzymes of the poly-ADP-ribose polymerase (PARP) super-family control many relevant cellular processes, but a precise understanding of their activities in different physiological or disease contexts is largely incomplete. We found that transcription of several PARP genes was dynamically regulated upon macrophage activation by several inflammatory stimuli. Specifically, PARP14 was strongly induced by endotoxin stimulation and translocated to the nucleus in stimulated cells. Quantitative mass spectrometry analysis showed that PARP14 bound to a group of interferon-stimulated gene (ISG)-encoded proteins, most with an unknown function, and it was required for their nuclear accumulation. Moreover, PARP14 depletion attenuated transcription of primary antiviral response genes regulated by the transcription factor IRF3, including Ifnb1, thus reducing IFNß production and activation of ISGs involved in the secondary antiviral response. Overall, these data hint at a role of PARP14 in the control of antimicrobial responses and specifically in nuclear activities of a subgroup of ISG-encoded proteins. Overall design: mRNA sequencing of differentially expressed genes in PARP14 WT RAW 264.7 cells, with or without LPS treatment
PARP14 Controls the Nuclear Accumulation of a Subset of Type I IFN-Inducible Proteins.
Specimen part, Cell line, Treatment, Subject
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