title: Cyclosporin-induced downregulation of the expression of E-cadherin during proliferation of edentulous gingival epithelium in rats.
abstract: BACKGROUND
  To examine the role of E-cadherin in epithelial hyperplasia of cyclosporin A (CsA)-induced gingival enlargement, mRNA and protein levels of E-cadherin, beta-catenin, proliferating cell nuclear antigen (PCNA), and Cyclin D1 were examined in the edentulous gingiva of rats following CsA treatment.
  
  
  METHODS
  Three weeks after the extraction of all maxillary molars, 20 male Sprague-Dawley rats were assigned to a CsA-fed group (30 mg/kg daily) or a control group. Five rats per group were sacrificed at weeks 1 and 4. Edentulous ridge specimens were taken, and the expression levels of E-cadherin, beta-catenin, Cyclin D1, and PCNA mRNAs were estimated by reverse transcription-polymerase chain reaction (RT-PCR). Tissue specimens of the week 4 groups were examined using immunohistochemical (IHC) staining for proteins.
  
  
  RESULTS
  The mRNA expression of E-cadherin was significantly weaker in the CsA-treated group than the control group at both times. Using IHC staining, a weaker level of membrane-bonded E-cadherin was also observed in the gingival epithelial cells in the CsA group than in controls. By contrast, significantly stronger beta-catenin and Cyclin D1 mRNA expressions and protein levels were found in CsA-treated rats than controls by RT-PCR and immunohistochemistry at week 4, whereas PCNA production was stronger at both times.
  
  
  CONCLUSIONS
  CsA treatment reduced the production of E-cadherin but increased the production of beta-catenin, Cyclin D1, and PCNA. Thus, CsA may downregulate E-cadherin gene expression, leading to the epithelial cell proliferation of gingival overgrowth.
authors: Institute of Oral Biology, National Yang-Ming University, Taipei, Taiwan, Republic of China.
authors: Hsiao-Pei
authors: HP
authors: Tu
authors: Yen-Teen
authors: YT
authors: Chen
authors: Yi-Shing
authors: YS
authors: Shieh
authors: Yu-Tang
authors: YT
authors: Chin
authors: Ren-Yeong
authors: RY
authors: Huang
authors: Shih-Fang
authors: SF
authors: Yang
authors: Ching-Hwa
authors: CH
authors: Gau
authors: Earl
authors: E
authors: Fu