title: Proteome analysis of the effects of all-trans retinoic acid on human germ cell tumor cell lines.
abstract: We analysed the effects of all-trans retinoic acid (ATRA) on proliferation and changes in the global proteome of the nullipotent human embryonal carcinoma cell line 2102Ep and the pluripotent cell line NTERA2 cl.D1 (NT2). Differentially expressed proteins were assessed by 2D-PAGE and mass spectrometry, followed by verification and analysis of protein modifications of proteins of the retinoid pathway. We established a proteome map of the germ cell tumor (GCT) cell line NT2 showing neuronal differentiation under ATRA treatment for 7days. Using bioinformatic analyses, we identified functional groups of altered proteins and potentially involved pathways, of which changes to the organization of the cytoskeleton and anti-apoptotic effects were the most prominent. Changes observed in the expression of factors involved in the retinoid pathway under ATRA, namely an upregulation of CRBP and CRABP2, were also reflected in GCT tissues of different histologies, providing further insight into factors involved in the differentiation of these pluripotent tumors.
  
  
  CONCLUSIONS
  Treatment of NT2 germ cell tumor cells with all-trans retinoic acid (ATRA) is a model to investigate differentiation. We analysed differentially expressed proteins by 2D-PAGE and mass spectrometry and provide a proteome map of NT2 cells under 7days of ATRA. By bioinformatic analyses, functional groups of proteins and involved pathways like changes to the cytoskeleton and anti-apoptotic effects were identified. Factors involved in the retinoid pathway, in particular upregulation of CRBP, CRABP1 and CRABP2, also showed differential expression in tumors with different histological subtypes, which provides insight into gene regulation under induced and spontaneous differentiation in germ cell tumors.
authors.affiliation: Department of Oncology, Hematology and Bone Marrow Transplantation with section Pneumology, Hubertus Wald-Tumor Zentrum (UCCH), University Hospital Eppendorf (UKE), Hamburg, Germany. Electronic address: Friedemann.honecker@zetup.ch.
authors.forename: Friedemann
authors.initials: F
authors.lastname: Honecker
authors.affiliation: Department of Oncology, Hematology and Bone Marrow Transplantation with section Pneumology, Hubertus Wald-Tumor Zentrum (UCCH), University Hospital Eppendorf (UKE), Hamburg, Germany.
authors.forename: Tina
authors.initials: T
authors.lastname: Rohlfing
authors.affiliation: Department of Clinical Chemistry/Central Laboratories, University Hospital Eppendorf (UKE), Hamburg, Germany.
authors.forename: Sönke
authors.initials: S
authors.lastname: Harder
authors.affiliation: Department of Oncology, Hematology and Bone Marrow Transplantation with section Pneumology, Hubertus Wald-Tumor Zentrum (UCCH), University Hospital Eppendorf (UKE), Hamburg, Germany.
authors.forename: Melanie
authors.initials: M
authors.lastname: Braig
authors.affiliation: Department of Pathology, Erasmus MC, University Medical Center Rotterdam, Josephine Nefkens Institute, Rotterdam, The Netherlands.
authors.forename: Ad J M
authors.initials: AJ
authors.lastname: Gillis
authors.affiliation: Department of Oncology, Hematology and Bone Marrow Transplantation with section Pneumology, Hubertus Wald-Tumor Zentrum (UCCH), University Hospital Eppendorf (UKE), Hamburg, Germany; Department of Pediatric Immunology, Allergology and Pneumology, Hannover Medical School, Hannover, Germany.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Glaesener
authors.affiliation: Department of Oncology, Hematology and Bone Marrow Transplantation with section Pneumology, Hubertus Wald-Tumor Zentrum (UCCH), University Hospital Eppendorf (UKE), Hamburg, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Barett
authors.affiliation: Department of Oncology, Hematology and Bone Marrow Transplantation with section Pneumology, Hubertus Wald-Tumor Zentrum (UCCH), University Hospital Eppendorf (UKE), Hamburg, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Bokemeyer
authors.affiliation: Department of Clinical Chemistry/Central Laboratories, University Hospital Eppendorf (UKE), Hamburg, Germany.
authors.forename: Friedrich
authors.initials: F
authors.lastname: Buck
authors.affiliation: Department of Oncology, Hematology and Bone Marrow Transplantation with section Pneumology, Hubertus Wald-Tumor Zentrum (UCCH), University Hospital Eppendorf (UKE), Hamburg, Germany; Department of Hematology and Oncology, University Hospital of the RWTH Aachen, Aachen, Germany.
authors.forename: Tim H
authors.initials: TH
authors.lastname: Brümmendorf
authors.affiliation: Department of Pathology, Erasmus MC, University Medical Center Rotterdam, Josephine Nefkens Institute, Rotterdam, The Netherlands.
authors.forename: Leendert H J
authors.initials: LH
authors.lastname: Looijenga
authors.affiliation: Department of Oncology, Hematology and Bone Marrow Transplantation with section Pneumology, Hubertus Wald-Tumor Zentrum (UCCH), University Hospital Eppendorf (UKE), Hamburg, Germany; Division of Hematology, University Hospital Zürich, Zürich, Switzerland. Electronic address: stefan.balabanov@usz.ch.
authors.forename: Stefan
authors.initials: S
authors.lastname: Balabanov
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D018236:Carcinoma, Embryonal / Q000378:metabolism* / Q000473:pathology; D002454:Cell Differentiation / Q000187:drug effects; D045744:Cell Line, Tumor; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D011499:Protein Processing, Post-Translational / Q000187:drug effects*; D020543:Proteome / Q000096:biosynthesis*; D013997:Time Factors; D014212:Tretinoin / Q000494:pharmacology*; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; D009363:Neoplasm Proteins; D020543:Proteome; D014212:Tretinoin
keywords: CRABP; Germ cell tumor; Proteomics; Retinoic acid