title: Increased expression of Smad proteins, and in particular Smad3, in oral lichen planus compared to normal oral mucosa.
abstract: BACKGROUND
  Oral lichen planus (OLP) is a chronic inflammatory disease of the oral mucosa which the World Health Organisation (WHO) considers a premalignant condition. One step in malignant development is so called epithelial mesenchymal transition (EMT), a process whereby epithelial cells acquire mesenchymal characteristics. EMT occurs during embryogenesis and wound healing but also in some human diseases such as cancer and fibrosis. A factor known to induce EMT is transforming growth factor-β (TGF-β), which uses the Smad proteins as mediators for its signalling. TGF-β is also often over-expressed in squamous cell carcinoma of the head and neck (SCCHN).
  
  
  METHODS
  In the present study we mapped expression of Smad proteins in OLP lesions by immunohistochemistry, and compared to expression in normal and sensitive oral mucosa. The latter group of patients had developed SCCHN after shorter or longer periods of diffuse oral symptoms. The aim was to see if there were any signs of EMT related changes in the OLP lesions, as judged by changes in the TGF-β pathway.
  
  
  CONCLUSIONS
  Changes in the TGF-β pathway related to EMT are seen in the very earliest stages of oral malignancy and become more severe as lesions progress.
authors.affiliation: Department of Odontology, Umeå University, Umeå, Sweden. karin.danielsson@odont.umu.se
authors.forename: K
authors.initials: K
authors.lastname: Danielsson
authors.forename: Y B
authors.initials: YB
authors.lastname: Wahlin
authors.forename: P J
authors.initials: PJ
authors.lastname: Coates
authors.forename: K
authors.initials: K
authors.lastname: Nylander
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000473:pathology; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D018450:Disease Progression; D058750:Epithelial-Mesenchymal Transition / Q000502:physiology; D005260:Female; D006258:Head and Neck Neoplasms / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D017676:Lichen Planus, Oral / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000473:pathology*; D011230:Precancerous Conditions / Q000473:pathology; D051785:Smad Proteins / Q000032:analysis*; D051899:Smad2 Protein / Q000032:analysis; D051900:Smad3 Protein / Q000032:analysis*; D051901:Smad4 Protein / Q000032:analysis; D051906:Smad7 Protein / Q000032:analysis; D016212:Transforming Growth Factor beta / Q000032:analysis; D055815:Young Adult
chemical_list: C497782:SMAD2 protein, human; C497790:SMAD3 protein, human; C497796:SMAD4 protein, human; C497806:SMAD7 protein, human; D051785:Smad Proteins; D051899:Smad2 Protein; D051900:Smad3 Protein; D051901:Smad4 Protein; D051906:Smad7 Protein; D016212:Transforming Growth Factor beta