title: Overexpression of SIRT1 is a poor prognostic factor for advanced colorectal cancer.
abstract: BACKGROUND
  Sirtuin 1 (SIRT1) has been reported to have diverse roles in various biological processes through deacetylation of histone and nonhistone proteins. However, the correlations among SIRT1 protein expression, clinicopathological parameters, and survival of colorectal cancer patients remain unclear.
  
  
  METHODS
  SIRT1 protein expression was measured by immunohistochemistry in a paraffin-embedded tissue microarray, including 120 paired colorectal cancer and normal mucosa tissues. The correlations among SIRT1 protein expression, clinicopathological features, and prognosis were analyzed.
  
  
  RESULTS
  All samples (100%) were positive for SIRT1, with variable staining in the cytoplasm rather than in the nucleus. There was significant difference in SIRT1 overexpression between adenocarcinomas and normal mucosal tissue (P < 0.01, χ(2) test). SIRT1 overexpression was more frequently observed in advanced-stage tumors (P = 0.046, 0.002, χ(2) test). SIRT1 overexpression was significantly correlated with poor overall survival (P = 0.013, log-rank test) and diseasefree survival (P = 0.012, log-rank test).
  
  
  CONCLUSIONS
  SIRT1 overexpression correlated with advanced stage and poor prognosis. SIRT1 may play an important role in the progression of colorectal cancer.
authors.affiliation: Department of Gastroenterological Surgery, Peking University People's Hospital, Beijing 100044, China.
authors.forename: Kewei
authors.initials: K
authors.lastname: Jiang
authors.affiliation: Department of Gastroenterological Surgery, Peking University People's Hospital, Beijing 100044, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Lyu
authors.affiliation: Department of Gastroenterological Surgery, Peking University People's Hospital, Beijing 100044, China.
authors.forename: Zhanlong
authors.initials: Z
authors.lastname: Shen
authors.affiliation: Department of Gastroenterological Surgery, Peking University People's Hospital, Beijing 100044, China.
authors.forename: Jizhun
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Gastroenterological Surgery, Peking University People's Hospital, Beijing 100044, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Central Laboratory, Peking University People's Hospital, Beijing 100044, China.
authors.forename: Jianqiang
authors.initials: J
authors.lastname: Dong
authors.affiliation: Department of Gastroenterological Surgery, Peking University People's Hospital, Beijing 100044, China.
authors.forename: Yichao
authors.initials: Y
authors.lastname: Yan
authors.affiliation: Department of Pathology, Peking University People's Hospital, Beijing 100044, China.
authors.forename: Fangfang
authors.initials: F
authors.lastname: Liu
authors.affiliation: Department of Gastroenterological Surgery, Peking University People's Hospital, Beijing 100044, China. Email: shanwang60@sina.com.
authors.forename: Shan
authors.initials: S
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000378:metabolism*; D015179:Colorectal Neoplasms / Q000378:metabolism* / Q000473:pathology*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D056564:Sirtuin 1 / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; D056564:Sirtuin 1