title: [Preliminary study of p16 gene expression in pituitary adenomas].
abstract: OBJECTIVE
  The inactivation and low expression of tumor suppressor gene p16 has been found to play an important role in the tumorigenesis of a wide variety of human tumors, but its association with human pituitary adenomas was not clear. This study was conducted to investigate the relationship between p16 gene expression and clinicopathologic features including invasiveness and recurrence in pituitary adenoma patients.
  
  
  METHODS
  The p16 mRNA and p16 protein expression levels were examined using reverse transcription polymerase chain reaction (RT-PCR) and Western Blot analysis respectively in 70 pituitary adenomas and 10 normal brain tissues.
  
  
  RESULTS
  Fifty-two of 70 (74.3%) tumor samples presented loss or low p16 mRNA and p16 protein. The invasive and recurrent adenomas had higher loss expression rates than noninvasive and nonrecurrent group respectively; however, there was no significant difference (P >0.05). Moreover, the mean diameter of adenomas without p16 expression was obviously larger than that of p16-positive tumors (22.1+/-7.2 mm versus 8.1+/-4.5 mm, P< 0.01). There was no association between p16 expression and other clinicopathologic features of pituitary adenomas.
  
  
  CONCLUSIONS
  These findings suggested that p16 down-regulation may play an important role in the initial tumorigenesis, growth, and biological behavior of pituitary adenomas.
authors.affiliation: Department of Neurosurgery, The First Affiliated Hospital of SuzhouUniversity, Suzhou, Jiansu, 215006, PR China. ywh699@hotmail.com
authors.forename: Wen-Hua
authors.initials: WH
authors.lastname: Yu
authors.forename: Guo-Zhen
authors.initials: GZ
authors.lastname: Hui
authors.forename: Qing
authors.initials: Q
authors.lastname: Wang
authors.forename: Si-Rong
authors.initials: SR
authors.lastname: Wu
mesh_terms: D000328:Adult; D000368:Aged; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology; D015536:Down-Regulation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics; D009364:Neoplasm Recurrence, Local; D010911:Pituitary Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000503:physiopathology; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D019941:Cyclin-Dependent Kinase Inhibitor p16; D009363:Neoplasm Proteins; D012333:RNA, Messenger