PTBP1 and PTBP2 control alternative splicing programs during neuronal development, but the cellular functions of most PTBP1/2-regulated isoforms remain unknown. We show that PTBP1 guides developmental gene expression by regulating the transcription factor Pbx1. We identify exons that are differentially spliced when mouse embryonic stem cells (ESCs) differentiate into neuronal progenitor cells (NPCs) and neurons, and transition from PTBP1 to PTBP2 expression. We define those exons controlled by PTBP1 in ESCs and NPCs by RNA-seq analysis after PTBP1 depletion and PTBP1 crosslinking-immunoprecipitation. We find that PTBP1 represses Pbx1 exon 7 and the expression of its neuronal isoform Pbx1a in ESC. Using CRISPR-Cas9 to delete regulatory elements for exon 7, we induce Pbx1a expression in ESCs, finding that this activates transcription of specific neuronal genes including known Pbx1 targets. Thus PTBP1 controls the activity of Pbx1 and suppresses its neuronal transcriptional program prior to differentiation. Overall design: 46C mESCs were differentiated in mNPCs. The mNPCs were treated with 10 nM control, Ptbp1, Ptbp2, or Ptbp1 and Ptbp2 siRNAs for 48 hours. The knockdowns were performed using 2 independent sets of siRNAs. Poly-A RNA was isolated for RNA-sequencing and splicing analyses.
The splicing regulator PTBP1 controls the activity of the transcription factor Pbx1 during neuronal differentiation.
No sample metadata fields
View SamplesMurine Pulmonary Responses to Ambient Baltimore Particulate Matter: Genomic Analysis and Contribution to Airway Hyperresponsiveness
Murine lung responses to ambient particulate matter: genomic analysis and influence on airway hyperresponsiveness.
No sample metadata fields
View SamplesPurpose: To investigate the gene regulatory networks during photoreceptor differentiation.
Targeting of GFP to newborn rods by Nrl promoter and temporal expression profiling of flow-sorted photoreceptors.
No sample metadata fields
View SamplesThe presence of some malignancies, such as cancer, impacts on peripheral blood mononuclear cells (PBMCs) gene expression profiling, suggesting the potential suitability of these genes as diagnostic and prognostic markers.
Transcriptional profiling of peripheral blood in pancreatic adenocarcinoma patients identifies diagnostic biomarkers.
Sex, Age, Specimen part, Disease, Disease stage
View SamplesParticulate Matter Triggers Carotid Body Dysfunction, Respiratory Dysynchrony and Cardiac Arrhythmias in Mice with Cardiac Failure
Particulate matter induces cardiac arrhythmias via dysregulation of carotid body sensitivity and cardiac sodium channels.
Age, Specimen part
View SamplesDysregulated oncogenic serine/threonine kinases play a pathological role in diverse forms of malignancies, including multiple myeloma (MM), and thus represent potential therapeutic targets. Here, we evaluated the biological and functional role of p21-activated kinase 4 (PAK4), and its potential as a new target in MM for clinical applications. PAK4 promoted MM cell growth and survival via activation of MM survival signaling pathways, including the MEK-ERK pathway. Furthermore, treatment with orally bioavailable PAK4 allosteric modulator (KPT-9274) significantly impacted MM cell growth and survival in a large panel of MM cell lines and primary MM cells alone and in the presence of bone marrow microenvironment. Intriguingly, we have identified FGFR3 as a novel binding partner of PAK4 and observed significant activity of KPT-9274 against t(4;14)-positive MM cells. These data support PAK4 as an oncogene in myeloma, and provide the rationale for the clinical evaluation of PAK4 modulator in myeloma.
Functional role and therapeutic targeting of p21-activated kinase 4 in multiple myeloma.
Specimen part, Cell line
View SamplesAlveolar rhabdomyosarcoma (aRMS) is a soft tissue sarcoma associated with the skeletal muscle lineage. The majority of aRMS tumors express the fusion protein PAX3-FOXO1 (PF), which has proven chemically intractable. As such, we identified proteins downstream from or cooperate with PF to support tumorigenesis, including SFRP3 (FRZB). Suppression of SFRP3 using lentivirally transduced shRNAs inhibits cell growth in vitro and tumor growth in vivo. This study aims to identify the genetic changes that underlie the SFRP3 suppression-mediated decreased cell growth. We analyzed changes using Gene Ontology (GO) enrichment and found the induced genes were enriched in striated muscle development/differentiation. In contrast, the repressed genes were enriched in response to stimulus and cell cycle/mitosis genes. We also observed as expected downregulation of SFRP3 (FRZB) but also downregulation of Wnt pathway-repressing genes such as CTBP2 (a transcriptional repressor of TCF, similar to CTBP1 ) and NAV2 (which is downstream from APC). Conversely, we noted upregulation of genes including CCND1 (cyclin D1) and SNAI2 (SLUG), both Wnt signaling target genes and WNT6, which is known to inhibit myoblast proliferation but induce myoblast elongation.
Secreted Frizzled-Related Protein 3 (SFRP3) Is Required for Tumorigenesis of PAX3-FOXO1-Positive Alveolar Rhabdomyosarcoma.
Disease, Cell line, Treatment
View SamplesAlveolar rhabdomyosarcoma (aRMS) is an aggressive sarcoma of skeletal muscle characterized by expression of the PAX3-FOXO1 fusion gene. Despite its discovery over almost 20 years ago, PAX3-FOXO1 remains an enigmatic tumor driver. Previously, we reported that PAX3-FOXO1 supports aRMS initiation by enabling bypass of cellular senescence. Here, we show that bypass occurs in part by PAX3-FOXO1-mediated upregulation of RASSF4, a Ras-association domain family (RASSF) member, which then suppresses the evolutionarily conserved mammalian Hippo/Mst1 pathway. RASSF4 loss-of-function activates Hippo/Mst1 and inhibits downstream YAP, causing aRMS cell cycle arrest and senescence. This is the first evidence for an oncogenic role for RASSF4, and a novel mechanism for Hippo signaling suppression in human cancer.
Alveolar rhabdomyosarcoma-associated PAX3-FOXO1 promotes tumorigenesis via Hippo pathway suppression.
Cell line, Treatment
View SamplesWe sought to obtain gene signature specific of high oxidative phsophorylation function.
Chemotherapy-Resistant Human Acute Myeloid Leukemia Cells Are Not Enriched for Leukemic Stem Cells but Require Oxidative Metabolism.
Cell line, Treatment
View SamplesIt has been hypothesized that chemotherapy resistant human acute myeloid leukemia (AML) cells are enriched in an immature phenotype, cellular quiescence and leukemic initiating cells (LICs). However, these hypotheses have never been validated completely in vivo. We have developed a physiologically relevant chemotherapeutic approach with cytosine arabinoside AraC using patient-derived xenograft (PDX) models. AraC-treated AML cells are not consistently enriched for either immature cells or quiescent cells. AraC treatment does not enrich for LICs as measured by limiting dilution in secondary transplantations. Rather chemotherapy resistant cells in vivo have high levels of reactive oxygen species (ROS) and a gene signature consistent with oxidative phosphorylation (OXPHOS). Treatment of human HIGH OXPHOS but not LOW OXPHOS AML cell lines showed chemotherapy resistance in vivo, showing that essential mitochondrial functions make significant contributions to AraC resistance in AML. Accordingly, targeting mitochondrial OXPHOS metabolism through the inhibition of mitochondrial protein synthesis, the electron transfer chain or fatty acid oxidation induced an energetic shift towards LOW OXPHOS and strongly enhanced anti-leukemic effects of AraC in AML cells. These results demonstrate that chemotherapy resistance in AML is not necessarily associated with stemness but is highly dependent on a distinct oxidative metabolism, and that the HIGH OXPHOS gene signature is a robust hallmark of the AraC response in PDX and a promising therapeutic avenue to treat AML residual disease.
Chemotherapy-Resistant Human Acute Myeloid Leukemia Cells Are Not Enriched for Leukemic Stem Cells but Require Oxidative Metabolism.
Specimen part, Disease
View Samples