title: Nanog: a potential biomarker for liver metastasis of colorectal cancer.
abstract: BACKGROUND
  At present, the relationship between Nanog expression and the biological behavior and prognosis of colorectal cancer is still unclear.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate the expression and regulatory effects of Nanog in colorectal cancer and the correlation between Nanog protein expression and the prognosis of patients with colorectal cancer.
  
  
  METHODS
  The differential expression of genes between CD133+ tumor cells and CD133- tumor cells were detected using RT(2) Profiler™ PCR Array. The Nanog mRNA expression level was detected by RT-PCR and the protein level was detected using immunohistochemistry staining. The relationship between Nanog expression and clinicopathological parameters of colorectal cancer was determined.
  
  
  RESULTS
  Nanog were expressed significantly higher in CD133+ tumor cells compared to CD133- tumor cells. It was observed that 72 (20.00 %) of the 360 cases positively expressed Nanog. Univariate analyses indicated that Nanog expression was related to histological grade, lymph node metastasis, TNM stage, and liver metastasis (P = 0.005, 0.001, 0.001 and 0.012, respectively). Spearman correlation analysis showed that Nanog expression has a linear correlation to liver metastasis (P = 0.001). After conducting multivariate analysis, histological grade, TNM stage, and Nanog were found to be related to liver metastasis (P = 0.020, 0.01 and 0.001, respectively). In the Cox regression test, the histological grade, Lymph node metastasis, TNM stage, liver metastasis, and Nanog were detected as the independent prognostic factors (P = 0.02, 0.045, 0.01, 0.001 and 0.001, respectively).
  
  
  CONCLUSIONS
  Nanog protein may be a potential biomarker for postoperative liver metastasis of colorectal cancer.
authors.affiliation: Department of Hepato-Biliary-Splenic Surgery, General Surgery, Shengjing Hospital, China Medical University, Shenyang 110004, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Xu
authors.forename: Chaoliu
authors.initials: C
authors.lastname: Dai
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhao
authors.forename: Songlin
authors.initials: S
authors.lastname: Peng
authors.forename: Changjun
authors.initials: C
authors.lastname: Jia
mesh_terms: D000071916:AC133 Antigen; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D015179:Colorectal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008113:Liver Neoplasms / Q000556:secondary*; D008198:Lymph Nodes / Q000473:pathology; D000071317:Nanog Homeobox Protein; D016017:Odds Ratio; D010455:Peptides / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012307:Risk Factors
chemical_list: D000071916:AC133 Antigen; D015703:Antigens, CD; D014408:Biomarkers, Tumor; D006023:Glycoproteins; D018398:Homeodomain Proteins; C486780:NANOG protein, human; D000071317:Nanog Homeobox Protein; C000606023:PROM1 protein, human; D010455:Peptides