title: [Expression and clinical significance of circadian gene Per2 in non-small cell lung cancer].
abstract: OBJECTIVE
  To detect the expression of Per2 in non-small cell lung cancer (NSCLC), and analyze its clinical significance.
  
  
  METHODS
  The expression of Per2 was determined in 60 NSCLC and 20 normal lung tissues by immunohistochemical assay, and the relationship between Per2 expression and clinicopathological features was analyzed.
  
  
  RESULTS
  The positive expression rates of Per2 in NSCLC and normal lung tissues were 71.7% and 95.0%, respectively (P < 0.05). The expression of Per2 in NSCLC was correlated with pathological differentiation and TNM stage (P < 0.05).
  
  
  CONCLUSIONS
  The expression of Per2 in NSCLC is decreased. The negative expression of Per2 may contribute to the development and invasion in NSCLC.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, the First Affiliated Hospital of Whenzhou Medical College, Wenzhou, China. chuangchi@163.com
authors.forename: Chuang
authors.initials: C
authors.lastname: Chi
authors.forename: Zhi-feng
authors.initials: ZF
authors.lastname: He
authors.forename: Yu
authors.initials: Y
authors.lastname: Liu
authors.forename: Xiao-ming
authors.initials: XM
authors.lastname: Lin
authors.forename: Cheng-chao
authors.initials: CC
authors.lastname: Sun
mesh_terms: D000328:Adult; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008175:Lung Neoplasms / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D056950:Period Circadian Proteins / Q000378:metabolism*; D012907:Smoking
chemical_list: C421902:PER2 protein, human; D056950:Period Circadian Proteins