title: Transcriptomic and CRISPR/Cas9 technologies reveal FOXA2 as a tumor suppressor gene in pancreatic cancer.
abstract: Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with low survival rates and limited therapeutic options. Thus elucidation of signaling pathways involved in PDAC pathogenesis is essential for identifying novel potential therapeutic gene targets. Here, we used a systems approach to elucidate those pathways by integrating gene and microRNA profiling analyses together with CRISPR/Cas9 technology to identify novel transcription factors involved in PDAC pathogenesis. FOXA2 transcription factor was found to be significantly downregulated in PDAC relative to control pancreatic tissues. Functional experiments revealed that FOXA2 has a tumor suppressor function through inhibition of pancreatic cancer cell growth, migration, invasion, and colony formation. In situ hybridization analysis revealed miR-199a to be significantly upregulated in pancreatic cancer. Bioinformatics and luciferase analyses showed that miR-199a negatively but directly regulates FOXA2 expression through binding in its 3'-untranslated region (UTR). Evaluation of the functional importance of miR-199a on pancreatic cancer revealed that miR-199a acts as an inhibitor of FOXA2 expression, inducing an increase in pancreatic cancer cell proliferation, migration, and invasion. Additionally, gene ontology and network analyses in PANC-1 cells treated with a small interfering RNA (siRNA) against FOXA2 revealed an enrichment for cell invasion mechanisms through PLAUR and ERK activation. FOXA2 deletion (FOXA2Δ) by using two CRISPR/Cas9 vectors in PANC-1 cells induced tumor growth in vivo resulting in upregulation of PLAUR and ERK pathways in FOXA2Δ xenograft tumors. We have identified FOXA2 as a novel tumor suppressor in pancreatic cancer and it is regulated directly by miR-199a, thereby enhancing our understanding of how microRNAs interplay with the transcription factors to affect pancreatic oncogenesis.
authors.affiliation: Center for Systems Biomedicine, Division of Digestive Diseases, David Geffen School of Medicine, University of California, Los Angeles, California;
authors.forename: Christina
authors.initials: C
authors.lastname: Vorvis
authors.affiliation: Centre for Biological Sciences, University of Southampton, Southampton, United Kingdom;
authors.forename: Maria
authors.initials: M
authors.lastname: Hatziapostolou
authors.affiliation: Center for Systems Biomedicine, Division of Digestive Diseases, David Geffen School of Medicine, University of California, Los Angeles, California;
authors.forename: Swapna
authors.initials: S
authors.lastname: Mahurkar-Joshi
authors.affiliation: Center for Systems Biomedicine, Division of Digestive Diseases, David Geffen School of Medicine, University of California, Los Angeles, California;
authors.forename: Marina
authors.initials: M
authors.lastname: Koutsioumpa
authors.affiliation: Department of Surgery, David Geffen School of Medicine, University of California, Los Angeles, California; and.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Williams
authors.affiliation: Department of Surgery, David Geffen School of Medicine, University of California, Los Angeles, California; and.
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Donahue
authors.affiliation: Department of Surgery, Stanford University School of Medicine, Stanford, California.
authors.forename: George A
authors.initials: GA
authors.lastname: Poultsides
authors.affiliation: Department of Surgery, David Geffen School of Medicine, University of California, Los Angeles, California; and.
authors.forename: Guido
authors.initials: G
authors.lastname: Eibl
authors.affiliation: Center for Systems Biomedicine, Division of Digestive Diseases, David Geffen School of Medicine, University of California, Los Angeles, California; diliopoulos@mednet.ucla.edu.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Iliopoulos
mesh_terms: D000818:Animals; D064113:CRISPR-Cas Systems; D045744:Cell Line, Tumor; D051542:Hepatocyte Nuclear Factor 3-beta / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D020935:MAP Kinase Signaling System; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D035683:MicroRNAs / Q000235:genetics; D010190:Pancreatic Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D059467:Transcriptome; D025521:Tumor Suppressor Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: C496502:FOXA2 protein, human; D035683:MicroRNAs; D025521:Tumor Suppressor Proteins; C531408:mirn199 microRNA, human; D051542:Hepatocyte Nuclear Factor 3-beta
keywords: CRISPR/Cas9; FOXA2; miR-199a; pancreatic cancer