title: Silencing of hepatic fate-conversion factors induce tumorigenesis in reprogrammed hepatic progenitor-like cells.
abstract: BACKGROUND
  Several studies have reported the direct conversion of mouse fibroblasts to hepatocyte-like cells with different degrees of maturation by expression of hepatic fate-conversion factors.
  
  
  METHODS
  We have used a combination of lentiviral vectors expressing hepatic fate-conversion factors with Oct4, Sox2, Klf4, and Myc to convert mouse embryonic fibroblasts into hepatic cells.
  
  
  RESULTS
  We have generated hepatic cells with progenitor-like features (iHepL cells). iHepL cells displayed basic hepatocyte functions but failed to perform functions characteristic of mature hepatocytes such as significant Cyp450 or urea cycle activities. iHepL cells expressed multiple hepatic-specific transcription factors and functional genes characteristic of immature hepatocytes and cholangiocytes, as well as high levels of Foxl1, Cd24a, and Lgr5, specific markers of hepatic progenitor cells. When transplanted into partial hepatectomized and hepatic irradiated mice, they differentiated into hepatocytes and cholangiocytes. However, iHepL cells formed malignant non-teratoma cell aggregations in one out of five engrafted livers and five out of five xenografts assays. All the cells in these tumors had silenced key hepatic fate-conversion factors, and lost hepatic features.
  
  
  CONCLUSIONS
  This study highlights the dangers of using pluripotency factors in reprogramming strategies when fate-conversion factors are silenced in vivo, and urges us to perform extensive tumorigenic tests in reprogrammed cells.
authors.affiliation: Unidad de Hepatología Experimental, Instituto de Investigación Sanitaria La Fe, CIBERehd, Avda. Fernando Abril Martorell 106, 46026, Valencia, Spain.|Present address: Anne McLaren Laboratory for Regenerative Medicine and Wellcome Trust-Medical Research Council, Cambridge Stem Cell Institute, University of Cambridge, West Forvie Site, Robinson Way, Cambridge, CB2 0SZ, UK.
authors.forename: Felipe
authors.initials: F
authors.lastname: Serrano
authors.affiliation: Differentiation and Cytometry Unit, Division of Hematopoietic Innovative Therapies, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT) and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBER-ER), Instituto de Investigación Sanitaria Fundación Jiménez Díaz (IIS-FJD, UAM), Avda. Complutense 40, 28040, Madrid, Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: García-Bravo
authors.affiliation: Unidad de Hepatología Experimental, Instituto de Investigación Sanitaria La Fe, CIBERehd, Avda. Fernando Abril Martorell 106, 46026, Valencia, Spain.
authors.forename: Marina
authors.initials: M
authors.lastname: Blazquez
authors.affiliation: Departamento de Biología Celular, Universidad de Valencia, Avda. Doctor Moliner 50, 46100, Burjassot, Spain.
authors.forename: Josema
authors.initials: J
authors.lastname: Torres
authors.affiliation: Unidad de Hepatología Experimental, Instituto de Investigación Sanitaria La Fe, CIBERehd, Avda. Fernando Abril Martorell 106, 46026, Valencia, Spain.
authors.forename: Jose V
authors.initials: JV
authors.lastname: Castell
authors.affiliation: Differentiation and Cytometry Unit, Division of Hematopoietic Innovative Therapies, Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT) and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBER-ER), Instituto de Investigación Sanitaria Fundación Jiménez Díaz (IIS-FJD, UAM), Avda. Complutense 40, 28040, Madrid, Spain.
authors.forename: Jose C
authors.initials: JC
authors.lastname: Segovia
authors.affiliation: Unidad de Hepatología Experimental, Instituto de Investigación Sanitaria La Fe, CIBERehd, Avda. Fernando Abril Martorell 106, 46026, Valencia, Spain. bort_ber@gva.es.
authors.forename: Roque
authors.identifier: http://orcid.org/0000-0002-7285-0536
authors.initials: R
authors.lastname: Bort
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D051927:CD24 Antigen / Q000235:genetics / Q000378:metabolism; D063646:Carcinogenesis / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D002454:Cell Differentiation; D065150:Cellular Reprogramming; D004622:Embryo, Mammalian; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism* / Q000637:transplantation; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D020868:Gene Silencing; D005822:Genetic Vectors / Q000737:chemistry / Q000378:metabolism; D006498:Hepatectomy; D022781:Hepatocytes / Q000378:metabolism / Q000473:pathology; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors / Q000235:genetics / Q000378:metabolism; D016086:Lentivirus / Q000235:genetics / Q000378:metabolism; D008297:Male; D051379:Mice; D016688:Mice, Inbred NOD; D050814:Octamer Transcription Factor-3 / Q000235:genetics / Q000378:metabolism; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism; D055748:SOXB1 Transcription Factors / Q000235:genetics / Q000378:metabolism; D013234:Stem Cells / Q000378:metabolism / Q000473:pathology; D013724:Teratoma / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D019076:Transgenes
chemical_list: D015415:Biomarkers; D051927:CD24 Antigen; C497890:Cd24a protein, mouse; D051858:Forkhead Transcription Factors; C099993:Foxl1 protein, mouse; C000715467:KLF4 protein, human; C000715468:Klf4 protein, mouse; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors; C493597:Lgr5 protein, mouse; C489427:MYC protein, human; D050814:Octamer Transcription Factor-3; C494174:Pou5f1 protein, mouse; D016271:Proto-Oncogene Proteins c-myc; D043562:Receptors, G-Protein-Coupled; D055748:SOXB1 Transcription Factors; C527783:Sox2 protein, mouse
keywords: Direct reprogramming; Hepatocyte; Progenitor; Tumorigenesis; Xenograft