title: [Immunohistochemical analysis of cell cycle-associated proteins p27 in oral cancer and precancer].
abstract: OBJECTIVE
  To evaluate the expression of p27 protein in oral precancerous lesions and oral squamous cell carcinoma (OSCC).
  
  
  METHODS
  Immunohistochemistry was used to detect p27, p53, murine double minute (MDM2) and p21 protein expression in a series of 13 specimens with simple hyperplasia, 44 with dysplasia and 48 with OSCC. An attempt was made to correlate the protein levels with clinicopathologic parameters and Ki-67 protein levels.
  
  
  RESULTS
  Positive p27 staining was present in 79.55% of the dysplasia samples, as well as in 81.25% of the OSCC samples. p27 protein overexpression in OSCC group was significantly higher than that in leukoplakia group (P < 0.001). The extent of p27 expression was positively associated with Ki-67 expression (P < 0.001). Cases with p27 overexpression displayed concurrent expression of p53 and/or MDM2 (P = 0.034) in OSCC group.
  
  
  CONCLUSIONS
  p27, p53, MDM2 and p21 may all play important roles in the genesis of OSCC. The alterations of one or more cell cycle regulators are prevalent in oral premalignant lesions and OSCC and the regulators can regulate each other.
authors.affiliation: Department of Oral Pathology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Hou
authors.forename: Yan
authors.initials: Y
authors.lastname: Gao
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology; D018797:Cell Cycle Proteins / Q000378:metabolism; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D009062:Mouth Neoplasms / Q000378:metabolism* / Q000473:pathology; D011230:Precancerous Conditions / Q000378:metabolism* / Q000473:pathology
chemical_list: D018797:Cell Cycle Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27