title: SIRT1 Expression Is Associated with Good Prognosis in Colorectal Cancer.
abstract: BACKGROUND
  Silent mating type information regulation 2 homolog 1 (SIRT1), an NAD+-dependent deacetylase, might act as a tumor promoter by inhibiting p53, but may also as a tumor suppressor by inhibiting several oncogenes such as β-catenin and survivin. Deleted in breast cancer 1 (DBC1) is known as a negative regulator of SIRT1.
  
  
  METHODS
  Immunohistochemical expressions of SIRT1, DBC1, β-catenin, surviving, and p53 were evaluated using 2 mm tumor cores from 349 colorectal cancer patients for tissue microarray.
  
  
  RESULTS
  Overexpression of SIRT1, DBC1, survivin, and p53 was seen in 235 (67%), 183 (52%), 193 (55%), and 190 (54%) patients, respectively. Altered expression of β-catenin was identified in 246 (70%) patients. On univariate analysis, overexpression of SIRT1 (p=0.029) and altered expression of β-catenin (p=0.008) were significantly associated with longer overall survival. Expression of SIRT1 was significantly related to DBC1 (p=0.001), β-catenin (p=0.001), and survivin (p=0.002), but not with p53. On multivariate analysis, age, tumor stage, differentiation, and expression of SIRT1 were independent prognostic factors significantly associated with overall survival.
  
  
  CONCLUSIONS
  SIRT1 overexpression is a good prognostic factor for colorectal cancer, and SIRT1 may interact with β-catenin and survivin rather than p53.
authors.affiliation: Department of Pathology, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Korea.
authors.forename: Wonkyung
authors.initials: W
authors.lastname: Jung
authors.forename: Kwang Dae
authors.initials: KD
authors.lastname: Hong
authors.forename: Woon Yong
authors.initials: WY
authors.lastname: Jung
authors.forename: Eunjung
authors.initials: E
authors.lastname: Lee
authors.forename: Bong Kyung
authors.initials: BK
authors.lastname: Shin
authors.forename: Han Kyeom
authors.initials: HK
authors.lastname: Kim
authors.forename: Aeree
authors.initials: A
authors.lastname: Kim
authors.forename: Baek-Hui
authors.initials: BH
authors.lastname: Kim
keywords: Adenocarcinoma; Beta catenin; Colon; DBC1; SIRT1