title: Oxytalan-positive peripheral ossifying fibromas express runt-related transcription factor 2, bone morphogenetic protein-2, and cementum attachment protein. An immunohistochemical study.
abstract: BACKGROUND
  The peripheral ossifying fibroma (POF) represents one of the most common lesions of the periodontal tissues that may originate from the gingival soft tissues, the periosteum, or the periodontal ligament.
  
  
  OBJECTIVE
  To investigate the immunohistochemical expression of runt-related transcription factor 2 (Runx-2), bone morphogenetic protein-2 (BMP-2), and cementum attachment protein (CAP) in oxytalan-positive POF, to establish the use of POF as an in vivo model for the study of the periodontal ligament.
  
  
  METHODS
  Thirty tumors that presented clinical and histologic features of POF, as well as oxytalan fibers, were included in the study. Immunohistochemical expression of Runx-2, BMP-2, and CAP was evaluated by light microscopy.
  
  
  RESULTS
  Runx-2, BMP-2, and CAP were abundantly expressed by POFs; 22 of 30 tumors expressed positive staining for Runx-2, twenty-six tumors for BMP-2, and twenty-five tumors for CAP. The expression of Runx-2 was abundant in POFs where bone was histologically present (P = 0.04) and of BMP-2 in POFs where dystrophic calcifications were present (P = 0.03).
  
  
  CONCLUSIONS
  It is suggested that oxytalan-positive POFs, purportedly originating from the periodontal ligament, express molecules that are specific to bone and cementum (Runx-2, BMP-2), or cementum only (CAP). Thus, the cell populations present in the lesion belong to the mineralized-tissue-forming cell lineages, the cementoblastic or osteoblastic lineage.
authors.affiliation: Department of Periodontology, School of Dentistry, University of Athens, Athens, Greece.
authors.forename: Ioanna A
authors.initials: IA
authors.lastname: Tsiligkrou
authors.affiliation: Department of Oral Pathology and Medicine, School of Dentistry, University of Athens, Athens, Greece.
authors.forename: Konstantinos I
authors.initials: KI
authors.lastname: Tosios
authors.affiliation: Department of Periodontology, School of Dentistry, University of Athens, Athens, Greece.
authors.forename: Phoebus N
authors.initials: PN
authors.lastname: Madianos
authors.affiliation: Department of Periodontology, School of Dentistry, University of Athens, Athens, Greece.
authors.forename: Ioannis A
authors.initials: IA
authors.lastname: Vrotsos
authors.affiliation: Department of Periodontology, School of Dentistry, University of Athens, Athens, Greece.
authors.forename: Vassilios G
authors.initials: VG
authors.lastname: Panis
mesh_terms: D055396:Bone Morphogenetic Protein 2 / Q000096:biosynthesis* / Q000235:genetics; D001859:Bone Neoplasms / Q000378:metabolism* / Q000473:pathology; D002113:Calcification, Physiologic; D002454:Cell Differentiation / Q000502:physiology; D050659:Core Binding Factor Alpha 1 Subunit / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D003739:Dental Cementum / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000096:biosynthesis*; D005260:Female; D018214:Fibroma, Ossifying / Q000378:metabolism* / Q000473:pathology; D005881:Gingiva / Q000378:metabolism / Q000473:pathology; D005887:Gingival Neoplasms / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D010006:Osteoblasts / Q000378:metabolism; D010513:Periodontal Ligament / Q000378:metabolism / Q000473:pathology; D017027:Protein Tyrosine Phosphatases / Q000096:biosynthesis* / Q000235:genetics; D012189:Retrospective Studies
chemical_list: C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D050659:Core Binding Factor Alpha 1 Subunit; D016326:Extracellular Matrix Proteins; C493709:RUNX2 protein, human; C437744:oxytalan; C404489:HACD1 protein, human; D017027:Protein Tyrosine Phosphatases
keywords: BMP-2; CAP; Runx-2; cementogenesis; osteogenesis; peripheral ossifying fibroma